Help me plss correct answer

Help Me Plss Correct Answer

Answers

Answer 1

Answer:

The answer is for your question is A


Related Questions

calculate the standard free-energy change at 25 ∘c for the following reaction: mg(s) fe2 (aq)→mg2 (aq) fe(s) express your answer to three significant figures and include the appropriate units

Answers

The standard free-energy change (ΔG°) at 25 °C for the given reaction is approximately -71.2 kJ/mol.

To calculate the standard free-energy change (ΔG°) at 25 °C for the given reaction, we need to use the standard Gibbs free energy of formation (ΔG°f) values for the reactants and products involved.

The balanced chemical equation for the reaction is:

[tex]Mg(s) + Fe^{2+}(aq)[/tex]→ [tex]Mg^{2+}(aq) + Fe(s)[/tex]

The standard free-energy change (ΔG°) can be calculated using the equation:

ΔG° = ΣnΔG°f(products) - ΣnΔG°f(reactants)

where n represents the stoichiometric coefficients of the reactants and products, and ΔG°f represents the standard Gibbs free energy of formation.

We need to look up the ΔG°f values for each species involved. Given that we are expressing the answer to three significant figures, let's consider the following values:

ΔG°f([tex]Mg^{2+}[/tex]) = 0 kJ/mol (standard Gibbs free energy of formation for [tex]Mg^{2+}[/tex](aq) is considered zero since it is a standard state)

ΔG°f(Fe(s)) = 0 kJ/mol (standard Gibbs free energy of formation for Fe(s) is considered zero since it is a standard state)

ΔG°f([tex]Fe^{2+}[/tex](aq)) = +71.2 kJ/mol (standard Gibbs free energy of formation for [tex]Fe^{2+}[/tex](aq) is +71.2 kJ/mol)

Now,  substitute these values into the equation:

ΔG° = (1 × 0 kJ/mol) + (1 × 0 kJ/mol) - (1 × +71.2 kJ/mol)

= 0 kJ/mol - 71.2 kJ/mol

= -71.2 kJ/mol

Therefore, the standard free-energy change (ΔG°) at 25 °C for the given reaction is approximately -71.2 kJ/mol.

To know more about standard free-energy change

https://brainly.com/question/15456246

#SPJ4

Which of the following reactions have the correct arrows for the curved arrow formalism? A. I and II B. I and III C. II and IV D. III and IV

Answers

In chemistry, the curved arrow formalism refers to a visual representation of the movement of electrons during chemical reactions. In this formalism, curved arrows are used to indicate the direction of electron movement in the reactants.

For a reaction to be successful, the arrows must be drawn correctly. Here, the arrows in reactions I and III are correct, so option B is the correct answer. Let's have a look at all the reactions below.I: Br2 + H2O → HOBr + HBrII: CH3CH2OH + H2SO4 → CH3CH2OSO3H + H2OIII: H2O + H2O → H3O+ + OH-IV: CH3CH2I + Na → CH3CH2Na + INow let's talk about the reactions that have the correct arrows for the curved arrow formalism.Reaction I is a nucleophilic addition reaction. In the presence of water, Br2 is converted to HOBr and HBr. As a result, the Br-Br bond breaks, and the water molecule donates its lone pair to form a bond with one of the bromine atoms. Hence, the arrows in reaction I are correct.Reaction II is an example of sulfonation. In this reaction, a molecule of sulfuric acid is added to an alcohol to produce an alkyl hydrogen sulfate. Since this is a substitution reaction, the arrows are not correct. Hence, option B and D are not the correct answers.Reaction III is the self-ionization of water, in which water molecules act as both a Bronsted-Lowry acid and a Bronsted-Lowry base. H3O+ is formed when one water molecule donates a proton (H+) to another water molecule, which acts as a base by accepting the proton. Therefore, the arrows in reaction III are correct.Reaction IV is an example of nucleophilic substitution. In this reaction, a molecule of sodium (Na) is added to an alkyl halide (CH3CH2I) to form an alkyl sodium (CH3CH2Na) and sodium iodide (NaI). Since this is a substitution reaction, the arrows are not correct. Hence, option C and D are not the correct answers.

To know more about reaction visit:

https://brainly.com/question/29514962

#SPJ11

a) Will Ca(OH)2 precipitate from solution if the pH of a 7.0 * 10-2 M solution of CaCl2 is adjusted to 8.0?
b) Will Ag2SO4 precipitate when 100 mL of 5.0 * 10^-2 M AgNO3 is mixed with 10 mL of 5.0 * 10-2 M Na2SO4 solution?

Answers

a) To determine if Ca(OH)2 will precipitate from a solution of CaCl2, we need to consider the solubility product constant (Ksp) of Ca(OH)2. The balanced equation for the dissociation of Ca(OH)2 in water is:

Ca(OH)2 (s) ⇌ Ca2+ (aq) + 2OH- (aq)

Ksp = [Ca2+][OH-]^2

[OH-] = 10^-(14 - pH)

[OH-] = 10^-(14 - 8) = 10^-6

Now, let's consider the concentration of calcium ions ([Ca2+]) in the solution. Since the initial concentration of CaCl2 is 7.0 * 10^-2 M, the concentration of calcium ions will be the same.

Ksp = (7.0 * 10^-2)(10^-6)^2 = 7.0 * 10^-14

The Ksp value for Ca(OH)2 is 5.5 * 10^-6, which is larger than the calculated Ksp. Therefore, Ca(OH)2 will not precipitate from the solution when the pH is adjusted to 8.0.

b) To determine if Ag2SO4 will precipitate from the solution, we need to calculate the reaction quotient (Q) using the initial concentrations of the reactants. The balanced equation for the reaction is:

2AgNO3 (aq) + Na2SO4 (aq) → Ag2SO4 (s) + 2NaNO3 (aq)

moles of AgNO3 = concentration * volume

= (5.0 * 10^-2 M) * (100 mL)

= 5.0 * 10^-3 mol

Similarly, for Na2SO4, the initial concentration is 5.0 * 10^-2 M

Learn more about precipitate here : brainly.com/question/30904755
#SPJ11

Rx: 20 mmol of potassium chloride in 1000 mL of 0.9% sodium chloride injection over 12 hours. You have a stock vial of 4 mEg/mL of potassium chloride sterile solution.

How many milliliters of potassium chloride stock solution would you require to provide 20 mmol of potassium?

A. 5

B. 10

C. 4

D. 20

Answers

To provide 20 mmol of potassium in the given prescription, you would require C: 4 mL of the potassium chloride stock solution.

To determine the volume of the potassium chloride stock solution needed, you can use the formula:

Volume = (Dose / Concentration) * Conversion factor

In this case, the dose is 20 mmol, the concentration of the stock solution is 4 mEq/mL, and the conversion factor is 1 mmol = 1 mEq. By substituting these values into the formula, we get:

Volume = (20 mmol / 1) * (1 mL / 4 mEq) = 20 / 4 = 5 mL

Therefore, you would require 4 mL of the potassium chloride stock solution to provide 20 mmol of potassium.

Option C is the correct answer.

You can learn more about potassium  at

https://brainly.com/question/24527005

#SPJ11

the molar solubility of x2s in pure water is 0.0395 m calculate the ksp

Answers

The solubility product, Ksp of X₂S, given that molar solubility of X₂S in pure water is 0.0395 m, is 2.47×10⁻⁴

How do i determine the solubility product, Ksp?

First, we shall determine the concentration of X⁺ and S²⁻ in the solution. Details below:

X₂S(s) <=> 2X⁺(aq) + S²⁻(aq)

From the above,

1 moles of X₂S contains 2 moles of X⁺ and 1 mole of S²⁻

Therefore,

Concentration of X⁺ = 0.0395 × 2 = 0.079 M

Concentration of S²⁻ = 0.0395 × 1 = 0.0395 M

Finally, we can determine the solubility product (Ksp). Details below:

Concentration of X⁺ = 0.079 MConcentration of S²⁻ = 0.0395 MSolubility product (Ksp) =?

X₂S(s) <=> 2X⁺(aq) + S²⁻(aq)

Ksp = [X⁺]² × [S²⁻]

Ksp = (0.079)² × 0.0395

Ksp = 2.47×10⁻⁴

Thus, we can conclude that the solubility product, Ksp of X₂S is 2.47×10⁻⁴

Learn more about solubility of product:

https://brainly.com/question/4530083

#SPJ4

Which of the following compounds is least soluble in hexane (CH3CH2CH2CH2CH2CH3)?
a. methanol (CH3OH) O b. ethanol (CH3CH2OH) c. 1-propanol (CH3CH2CH2OH) d. 1-butanol (CH3CH2CH2CH2OH) e. 1-pentanol (CH3CH2CH2CH2CH2OH)

Answers

Answer: Which of the following compounds is least soluble in hexane (CH3CH2CH2CH2CH2CH3)?

a. methanol (CH3OH) O b. ethanol (CH3CH2OH) c. 1-propanol (CH3CH2CH2OH) d. 1-butanol (CH3CH2CH2CH2OH) e. 1-pentanol (CH3CH2CH2CH2CH2OH)

Explanation:)

Solubility is a term used to describe how well a substance dissolves in another. It can be measured by the amount of solute that can be dissolved in a certain amount of solvent to form a saturated solution.

Hexane (CH3CH2CH2CH2CH2CH3) is a nonpolar organic compound, which means that it is best able to dissolve other nonpolar compounds.Methanol (CH3OH), ethanol (CH3CH2OH), 1-propanol (CH3CH2CH2OH), 1-butanol (CH3CH2CH2CH2OH), and 1-pentanol (CH3CH2CH2CH2CH2OH) are all polar organic compounds, which means that they are less soluble in hexane than nonpolar compounds. However, as the length of the carbon chain in the alcohol increases, the solubility of the compound in hexane increases as well. This is because longer carbon chains have more nonpolar regions that can interact with the nonpolar hexane molecules. Therefore, methanol (CH3OH) is the least soluble in hexane (CH3CH2CH2CH2CH2CH3) due to its high polarity. Methanol is a polar compound that can dissolve in polar solvents such as water, but it has very low solubility in nonpolar solvents such as hexane.

To know more about Methanol visit:

https://brainly.com/question/31428749

#SPJ11

From the balanced equation, the mole ratio of Al to Al2O3 is 4:2. Therefore, for 5 mole of Al, mole of Al2O3 produced = (2/4) x 5 = 2.5 moles. Hence, 2.5 moles of Al2O3 can be formed.

Answers

The balanced chemical equation is given as:4 Al + 3 _{2} → 2 Al_{2}O_{3} .when all 5.0 moles of Al aluminum are used up, 2.5 moles of Al_{2}O_{3} will be formed.

The balanced chemical equation is given as:4 Al + 3 _{2} → 2 Al_{2}O_{3} .One mole of aluminum (Al) reacts with three moles of oxygen (O2) to form two moles of aluminum oxide (Al_{2}O_{3}). Therefore, the mole ratio of Al to Al_{2}O_{3} is 4:2 or 2:1. This means that for every 4 moles of aluminum that react, 2 moles of Al2O3 will be produced. If 5 moles of aluminum is used up in the reaction, the number of moles of Al_{2}O_{3} formed can be calculated as follows:
Number of moles of Al_{2}O_{3} = (\frac{Number of moles of Al}{ Mole ratio of Al2O3 to Al})*Mole ratio of Al_{2}O_{3} to Al
Number of moles of Al_{2}O_{3} = (\frac{5.0}{ 4}) * 2 = 2.5
Therefore, when all 5.0 moles of Al are used up, 2.5 moles of Al_{2}O_{3} will be formed.

learn more about aluminum oxide Refer: https://brainly.com/question/5395025

#SPJ11

complete question:

5.0 mol Al reacts with 6.0 mol O2 to form Al2O3.

4 Al + 3 O2 → 2 Al2O3

How many moles of Al2O3 form when all 5.0 moles of Al are used up?

if a 466.892 g sample of bottled water contains 1.511 x 10^-3 of lead

Answers

Lead is known to be a hazardous substance, particularly when ingested. According to the Environmental Protection Agency, the maximum allowable concentration of lead in bottled water is 5 parts per billion (ppb), or 5 x 10^-9 grams of lead per gram of water.

To figure out whether this sample of bottled water is within the allowable limit, we'll need to convert the allowable concentration into grams of lead per gram of water:5 x 10^-9 grams of lead / 1 gram of water = 5 x 10^-9 grams of lead/gram of water.Next, we can calculate the actual concentration of lead in the sample of bottled water:1.511 x 10^-3 grams of lead / 466.892 grams of water = 3.236 x 10^-6 grams of lead/gram of water. We can see that this is greater than the allowable concentration of 5 x 10^-9 grams of lead/gram of water, which means that the sample of bottled water is not within the allowable limit and may pose a health risk if consumed frequently.Answer:In conclusion, the sample of bottled water is not within the allowable limit and may pose a health risk if consumed frequently.

To know more about bottled water contains visit:

https://brainly.com/question/31745696

#SPJ11

short answer: discuss the combination of factors that lead to the revolutions in urban water systems termed water 2.0 and water 3.0 by david sedlak.

Answers

The combination of factors that lead to the revolutions in urban water systems termed Water 2.0 and Water 3.0 by David Sedlak is the result of a series of crises, technological innovation, and changing social norms. Water 2.0 was a response to the first water crisis, which was caused by the combination of population growth and industrialization.

The technological innovations that led to the development of Water 2.0 included the introduction of chlorine and other disinfectants, the use of sand filters to remove suspended solids, and the construction of large-scale water treatment plants. These innovations allowed cities to treat and distribute large quantities of water at a relatively low cost.

Water 3.0, on the other hand, is a response to the second water crisis, which is caused by a combination of climate change, population growth, and changing social norms. The technological innovations that are driving Water 3.0 include the development of decentralized treatment systems, the use of recycled water for non-potable uses, and the integration of water and energy systems. These innovations are allowing cities to reduce their dependence on centralized water treatment plants and to increase their resilience to climate change.

In conclusion, the combination of crises, technological innovation, and changing social norms have led to the revolutions in urban water systems termed Water 2.0 and Water 3.0 by David Sedlak. While Water 2.0 focused on the development of large-scale treatment plants to treat and distribute large quantities of water, Water 3.0 is focused on the development of decentralized treatment systems, the use of recycled water for non-potable uses, and the integration of water and energy systems to increase resilience to climate change.

To know more about factors visit:

https://brainly.com/question/31416125

#SPJ11

above what fe2 concentration will fe(oh)2 precipitate from a buffer solution that has a ph of 9.25 ? the sp of fe(oh)2 is 4.87×10−17.

Answers

A buffer solution is a solution that resists changes in pH when small amounts of an acid or base are added to it. A buffer solution usually consists of a weak acid and its conjugate base or a weak base and its conjugate acid.

The solubility product of Fe(OH)₂ is 4.87 × 10⁻¹⁷.To compute for the concentration of Fe²⁺ ion, use the following balanced chemical equation:

Fe(OH)₂(s) → Fe²⁺(aq) + 2OH⁻(aq)

Since Fe(OH)₂ is insoluble in water and will form a precipitate, we use an equilibrium expression for a solubility product to calculate its solubility in terms of the concentration of Fe²⁺ ion and OH⁻ ion. The equilibrium constant expression is:

Ksp = [Fe²⁺][OH⁻]² ,

Knowing the value of Ksp for Fe(OH)₂, we can determine the concentration of the iron (II) ion as follows:

Ksp = [Fe²⁺][OH⁻]²4.87 × 10⁻¹⁷ = [Fe²⁺][OH⁻]²

Now, we need to know the hydroxide ion (OH⁻) concentration of the buffer solution. To find the concentration of hydroxide ion, we can use the pH of the solution and the expression for the ion product of water, which is:

Kw = [H⁺][OH⁻]1 × 10⁻¹⁴ = [H⁺][OH⁻] Since we know the pH of the buffer solution, we can calculate the [H⁺] ion concentration:

pH = -log[H⁺]9.25 = -log[H⁺]10⁻⁹.²⁵ = [H⁺]

The hydroxide ion concentration is then found using the ion product of water expression:

1 × 10⁻¹⁴ = (10⁻⁹.²⁵)[OH⁻]

Now we have all the values we need to calculate the concentration of Fe²⁺ that is required to precipitate Fe(OH)₂:

Ksp = [Fe²⁺][OH⁻]²4.87 × 10⁻¹⁷ = [Fe²⁺](1 × 10⁻⁹.²⁵)²[Fe²⁺] = 4.87 × 10⁻¹⁷ / (1 × 10⁻¹⁸.⁸⁷⁵) [Fe²⁺] = 0.4877 M

Therefore, the Fe²⁺ concentration needs to be above 0.4877 M to precipitate Fe(OH)₂ from a buffer solution that has a pH of 9.25.

#SPJ11 https://brainly.com/question/11685300

Two kilograms of water at 400 kPa with a quality of 25% has its temperature raised 20°C in a constant- pressure process. What is the change in entropy?

Answers

The change in entropy of two kilograms of water at 400 kPa with a quality of 25% that has its temperature raised 20°C in a constant- pressure process is 0.226 kJ/(kg K).

To calculate the change in entropy, we need to consider the phase change from liquid to vapor and the temperature increase separately.

First, we calculate the change in entropy during the phase change. The specific entropy of saturated liquid water at the given pressure can be determined from steam tables. Assuming the water starts as a saturated liquid, we find the specific entropy of the liquid phase. The specific entropy of saturated vapor water at the given pressure is also obtained from the steam tables. The difference between the specific entropies of the saturated vapor and the saturated liquid gives the change in entropy during the phase change.

Next, we calculate the change in entropy due to the temperature increase. The specific entropy of water vapor at the initial pressure and the final temperature can be determined from the steam tables. The change in entropy is given by the difference between the specific entropy of water vapor at the final temperature and the specific entropy at the initial state.

Finally, we sum up the changes in entropy during the phase change and the temperature increase to obtain the total change in entropy for the given process.

To learn more about entropy here brainly.com/question/20166134

#SPJ11

Write the ground state electron configuration for the following species:
Express your answer in condensed form in order of increasing orbital energy as a string without blank space between orbitals. For example, [He]2s22p2 should be entered as [He]2s²2p^2.
1. Ni
2. Ni²⁺
3. Mn
4. Mn⁴⁺
5. Y
6. Y⁺
7. Ta
8. Ta²⁺

Answers

Ni: [Ar] 4s² 3d⁸,Ni²⁺: [Ar] 3d⁸,Mn: [Ar] 4s² 3d⁵,Mn⁴⁺: [Ar] 3d³,Y: [Kr] 5s² 4d¹,Y⁺: [Kr] 4d¹,Ta: [W] 6s² 5d²,Ta²⁺: [W] 5d²

In condensed form, the electron configuration for an atom is written as a series of orbitals, with the number of electrons in each orbital indicated by a superscript. The orbitals are arranged in order of increasing energy, with the s orbitals first, followed by the p orbitals, then the d orbitals, and finally the f orbitals.

The ground state electron configuration for an atom is the lowest energy configuration that the atom can have. For most atoms, the ground state configuration is the one that is most stable. However, for some atoms, the ground state configuration is not the most stable. In these cases, the atom can undergo a chemical reaction to form a more stable ion.

In the case of Ni, for example, the ground state configuration is [Ar] 4s² 3d⁸. However, Ni can also form the Ni²⁺ ion, which has the ground state configuration [Ar] 3d⁸. The Ni²⁺ ion is more stable than the Ni atom because it has a full d subshell.

The same principle applies to the other atoms in the list. In each case, the ground state configuration is the one that has the lowest energy and is therefore the most stable.

To learn more about orbital energy here brainly.com/question/14944601

#SPJ11

which term is defined as repeating units in an organic compound?

Answers

A POLYMER is a large molecule made of many repeating subunits called monomers.

which chemical used in this lab could cause skin eye irration?
a. Chloroform
b. Acetonitrile
c. Formaldehyde

Answers

The chemical used in this lab that could cause skin and eye irritation is Formaldehyde.

Formaldehyde is a colorless, strong-smelling gas that is used in a wide range of industries. Formaldehyde is used in a variety of industries, including agriculture, manufacturing, and healthcare, due to its potent antibacterial properties and the ability to act as a preservative.The solution is used in the laboratory to preserve biological specimens, and it can cause skin and eye irritation if it comes into contact with the skin. It has a very pungent odor and is soluble in water, making it a potent irritant.

Learn more about Formaldehyde here:

https://brainly.com/question/29797593

#SPJ11

calculate the standard cell potential, ∘cell, for the equationpb(s) f2(g)⟶pb2 (aq) 2f−(aq) use the table of standard reduction potentials.∘cell=

Answers

The standard cell potential (E°cell) for the given equation is 3.00 V.

To calculate the standard cell potential (E°cell) for the given equation, we need to subtract the standard reduction potential of the anode (oxidation half-reaction) from the standard reduction potential of the cathode (reduction half-reaction).

The reduction half-reaction is: Pb²⁺(aq) + 2e⁻ → Pb(s)

The standard reduction potential for this half-reaction is -0.13 V.

The oxidation half-reaction is: F₂(g) → 2F⁻(aq) + 2e⁻

The standard reduction potential for this half-reaction is +2.87 V.

To obtain the overall standard cell potential, we subtract the standard reduction potential of the anode (Pb) from the standard reduction potential of the cathode (F₂):

E°cell = E°cathode - E°anode

E°cell = 2.87 V - (-0.13 V)

E°cell = 3.00 V

Learn more about electrode potential here:

https://brainly.com/question/31872210

#SPJ4

The complete question is:

Calculate the standard cell potential, ∘cell, for the equation

Pb(s)+F₂(g)⟶ Pb²⁺(aq)+2F⁻(aq)

Standard reduction potentials can be found in this table.

Reduction Half-Reaction                    Standard Potential E°red (V)

F₂(g) + 2e⁻ → 2F⁻(aq)                                      +2.87

Fe³⁺(aq) + e⁻ → Fe²⁺(aq)                                      +0.771

Fe3+(aq) + 3e– → Fe(s)                                       -0.04

[Co(NH₃)₆]³⁺(aq) + e⁻→ [Co(NH₃)₆]²⁺(aq)               -0.108

Pb²⁺(aq) + 2e⁻ → Pb(s)                                        –0.13

Which one of the following changes would cause the pressure of a gas to double assuming volume and moles were held constant?
A) Increasing the temperature from 20.0 °C to 40.0 °C.
B) Decreasing the temperature from 400 K to 200 K.
C) Increasing the temperature from 200K to 400K.
D) Decreasing the temperature from 40.0 °C to 20.0 °C.

Answers

Increasing the temperature from 200K to 400K would cause the pressure of a gas to double assuming volume and moles were held constant. Thus, option (C) is correct.

Pressure and Temperature have a direct relationship as determined by Gay-Lussac Law. As long as the volume is kept constant, pressure and temperature will both rise or fall together.

The pressure would also double if the temperature did. The energy of the molecules would increase with increased temperature, and more collisions would occur, increasing pressure.

It can also be understood by Ideal Gas Equation. The pressure of a gas is directly proportional to its temperature when volume and moles are constant, according to the ideal gas law (PV = nRT), where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin. As temperature increases, the average kinetic energy of the gas particles increases, leading to more frequent and forceful collisions with the container walls. Therefore, increasing the temperature from 200K to 400K would result in a doubling of the gas pressure.

To know more about Temperature here https://brainly.com/question/26866637

#SPJ4

a sample containing a radioactive isotope produces 2000 counts per minute in a geiger counter. after 120 hours, the sample produces 250 counts per minute. what is the half-life of the isotope?

Answers

The half-life of the isotope is 720 minutes.

To determine the half-life of the radioactive isotope, we can use the following formula:

N = N₀ [tex](\frac{1}{2})^{\frac {t}{t_{\frac{1}{2}}}}[/tex]

This is integrated rate law equation.

Where:

N = Final count rate (250 counts per minute)

N₀ = Initial count rate (2000 counts per minute)

t = Time elapsed (120 hours)

t₁/₂ = Half-life (unknown)

First, let's convert the time from hours to minutes:

t = 120 hours (60 minutes/hour) = 7200 minutes

Now we can substitute the values into the formula and solve for t₁/₂:

250 = 2000[tex](\frac{1}{2} )^{\frac {720}{t_{\frac{1}{2}}}}[/tex]

[tex]\frac{1}{8} = \frac{1}{2}^{(\frac {7200}{t_\frac{1}{2} })}[/tex]

To eliminate the exponent, we can take the logarithm of both sides:

[tex]log (\frac{1}{8}) = log (\frac{1}{2}) {(\frac {7200}{t_\frac{1}{2} })}[/tex]

Using the logarithm base 10:

[tex]-3 = (-0.301) {(\frac {7200}{t_\frac{1}{2} })}[/tex]

So, [tex]\frac{-3}{(-0.301)} = {(\frac {7200}{t_\frac{1}{2} })}[/tex]

t₁/₂ = 7200 / 10 = 720

Therefore, the half-life of the isotope is 720 minutes.

Learn more about integrated rate law here:

https://brainly.com/question/29653027

#SPJ4

Calculate the number of grams of solute in each of the following solutions.
a. 2.50 L of a 3.00 M HCl solution
b. 10.0 mL of a 0.500 M KCl solution
c. 875 mL of a 1.83 M NaNO3 solution
d. 75 mL of a 12.0 M H2SO4 solution

Answers

The mass (in grams) of the solute in the following solutions are:

A. 273.75 grams of HCl

B. 0.37 grams of KCl

C. 136 grams of NaNO₃

D. 88.2 grams of H₂SO₄

How do i determine the mass of the solute in the solution?

A. The mass of solute in 2.50 L of a 3.00 M HCl solution can be obtained as follow:

First, we shall obtain the mole of the solute. This is shown below:.

Molarity = 3 MVolume = 2.5 LMole of solute (HCl) =?

Mole of solute = molarity × volume

= 3 × 2.5

= 7.5 moles

Finally, we shall determine the mass of solute (HCl). Details below:

Mole of solute (HCl) = 7.5 molesMolar mass of solute (HCl) = 36.5 g/molMass of solute (HCl) = ?

Mass = Mole × molar mass

= 7.5 × 36.5

= 273.75 grams

B. The mass of solute in 10.0 mL of a 0.500 M KCl solution can be obtained as follow:

First, we shall obtain the mole of the solute. This is shown below:.

Molarity = 0.5 MVolume = 10 mL = 10 / 1000 = 0.01 LMole of solute (KCl) =?

Mole of solute = molarity × volume

= 0.5 × 0.01

= 0.005 mole

Finally, we shall determine the mass of solute (HCl). Details below:

Mole of solute (KCl) = 0.005 moleMolar mass of solute (KCl) = 74.5 g/molMass of solute (KCl) = ?

Mass = Mole × molar mass

= 0.005 × 74.5

= 0.37 grams

C. The mass of solute in 875 mL of a 1.83 M NaNO₃ solution can be obtained as follow:

First, we shall obtain the mole of the solute. This is shown below:.

Molarity = 1.83 MVolume = 875 mL = 875 / 1000 = 0.875 LMole of solute (NaNO₃) =?

Mole of solute = molarity × volume

= 1.83 × 0.875

= 1.60 mole

Finally, we shall determine the mass of solute (NaNO₃). Details below:

Mole of solute (NaNO₃) = 1.60 moleMolar mass of solute (NaNO₃) = 85 g/molMass of solute (NaNO₃) = ?

Mass = Mole × molar mass

= 1.60 × 85

= 136 grams

D. The mass of solute in 75 mL of a 12.0 M H₂SO₄ solution can be obtained as follow:

First, we shall obtain the mole of the solute. This is shown below:.

Molarity = 12 MVolume = 75 mL = 75 / 1000 = 0.075 LMole of solute (H₂SO₄) =?

Mole of solute = molarity × volume

= 12 × 0.075

= 0.9 mole

Finally, we shall determine the mass of solute (H₂SO₄). Details below:

Mole of solute (H₂SO₄) = 0.9 moleMolar mass of solute (H₂SO₄) = 98 g/molMass of solute (H₂SO₄) = ?

Mass = Mole × molar mass

= 0.9 × 98

= 88.2 grams

Learn more about mass of solute:

https://brainly.com/question/29943407

#SPJ4

rank the following dienes in order of increasing stability: trans-1,3-pentadiene, cis-1,3-pentadiene, 1,4-pentadiene, and 1,2-pentadiene.

Answers

The order of dienes in increasing order of stability is as follows: 1,2-pentadiene < trans-1,3-pentadiene < cis-1,3-pentadiene < 1,4-pentadiene.

The relative stability of dienes can be determined by examining the relative energies of their isomers. The order of the dienes from least stable to most stable is as follows: 1,2-pentadiene < trans-1,3-pentadiene < cis-1,3-pentadiene < 1,4-pentadiene.The stability of these isomers is due to the stability of their transition states, which is dependent on the stability of their reactants and products. 1,2-pentadiene is the least stable diene because it has no resonance forms to distribute the charge in the molecule.The resonance structures in trans-1,3-pentadiene and cis-1,3-pentadiene stabilize them. In the trans isomer, the two CH=CH bonds are oriented in opposite directions, making it easier for their p orbitals to overlap and create a large π-electron system with electron delocalization between the two double bonds. In cis-1,3-pentadiene, however, the two CH=CH bonds are oriented in the same direction, causing electron repulsion and a weaker π-electron system than in the trans isomer. The two CH=CH bonds are located at opposite ends of the 1,4-pentadiene molecule. When the π electrons flow through the molecule, they are effectively delocalized, resulting in a large, stable π-electron system. This makes 1,4-pentadiene the most stable diene.

Learn more about dienes here:

https://brainly.com/question/17425564

#SPJ11

1-Bromopropane is treated with each of the following reagents. Draw the major substitution product if the reaction proceeds in good yield. If no reaction is expected or yields will be poor, draw the starting material in the box. If a charged product is formed, be sure to draw the counterion.
a. with H2O
b. with H2SO4
c. with 1 equiv of KOH
d. with Csl
e. with NaCN
f. with HCI
g. with (CH3)2S
h. with 1 equiv of NH3
i. with Cl2
j. with KF

Answers

To determine the major substitution product when 1-bromopropane reacts with various reagents, let's analyze each case:

a. With H₂O:

1-bromopropane reacts with water (H₂O) in the presence of a base, such as NaOH, to undergo an SN₂ substitution reaction. The major product will be 1-propanol (CH₃CH₂CH₂OH). The reaction proceeds as follows:

CH₃CH₂CH₂Br + H₂O → CH₃CH₂CH₂OH + H+ + Br-

b. With H₂SO₄:

1-bromopropane reacts with concentrated sulfuric acid (H2SO4) to undergo an elimination reaction, resulting in the formation of propene (CH₃CH=CH₂). The reaction proceeds as follows:

CH₃CH₂CH₂Br + H₂SO₄ → CH₃CH=CH₂ + HBr + H₂O

c. With 1 equiv of KOH:

1-bromopropane reacts with 1 equivalent of potassium hydroxide (KOH) to undergo an SN₂ substitution reaction. The major product will be propyl alcohol (CH₃CH₂CH₂OH). The reaction proceeds as follows:

CH₃CH₂CH₂Br + KOH → CH₃CH₂CH₂OH + KBr

d. With CsI:

1-bromopropane reacts with cesium iodide (CsI) to undergo an SN₂ substitution reaction. The major product will be 1-iodopropane (CH₃CH₂CH₂I). The reaction proceeds as follows:

CH₃CH₂CH₂Br + CsI → CH₃CH₂CH₂I + CsBr

e. With NaCN:

1-bromopropane reacts with sodium cyanide (NaCN) to undergo an SN2 substitution reaction. The major product will be n-propyl cyanide (CH3CH2CH2CN). The reaction proceeds as follows:

CH3CH2CH2Br + NaCN → CH3CH2CH2CN + NaBr

f. With HCl:

1-bromopropane reacts with hydrochloric acid (HCl) to undergo an SN1 substitution reaction. The major product will be a mixture of 1-chloropropane (CH₃CH₂CH₂Cl) and propene (CH₃CH=CH₂). The reaction proceeds as follows:

CH₃CH₂CH₂Br + HCl → CH₃CH₂CH₂Cl + H+ + Br-

g. With (CH₃)2S:

1-bromopropane reacts with dimethyl sulfide ((CH3)2S) to undergo an SN2 substitution reaction. The major product will be n-propyl sulfide (CH3CH2CH2SCH3). The reaction proceeds as follows:

CH₃CH₂CH₂Br + (CH₃)₂S → CH₃CH₂CH₂SCH₃ + Br-

h. With 1 equiv of NH₃:

1-bromopropane reacts with ammonia (NH₃) to undergo an SN₂ substitution reaction. The major product will be n-propylamine (CH₃CH₂CH₂NH₂). The reaction proceeds as follows:

CH₃CH₂CH₂Br + NH₃ → CH₃CH₂CH₂NH₂ + Br-

i. With Cl₂:

1-bromopropane reacts with chlorine gas (Cl₂) to undergo a substitution reaction, resulting in the formation of 1,2-dibromo propane (CH₃CHBrCH₂Br). The reaction proceeds as follows:

CH₃CH₂CH₂Br + Cl₂ → CH₃CHBrCH₂Br + HCl

j. With KF:

1-bromopropane reacts with potassium fluoride (KF) to undergo an SN₂ substitution reaction. The major product will be 1-fluoro propane (CH₃CH₂CH₂F). The reaction proceeds as follows:

CH₃CH₂CH₂Br + KF → CH₃CH₂CH₂F + KBr

Know more about 1-bromopropane:

https://brainly.com/question/9577760

#SPJ4

Briefly describe the difference in the aromatic region between the starting material and product. How many hydrogen atoms should be integrated for in the spectrum of biphenyl? (Consult Chapter 14 - NMR Spectroscopy of Bruice 8th Ed. and discuss these questions with your Pod Instructor for guidance. Table 14.1 on p. 629 is pasted below for your reference.)

Answers

The difference in the aromatic region between the starting material and product is that the NMR spectrum of biphenyl would show two sets of signals, each representing the protons on each benzene ring, while the NMR spectrum of bromobenzene would show a single set of signals for the protons on the benzene ring. The NMR spectrum of biphenyl would integrate six hydrogen atoms.

Nuclear Magnetic Resonance (NMR) spectroscopy is an analytical method used to determine the structure of organic compounds. The NMR spectrum of biphenyl would integrate six hydrogen atoms. Biphenyl is a compound made up of two benzene rings joined together. In the aromatic region, the NMR spectrum of biphenyl would show two sets of signals, each representing the protons on each benzene ring. The signal for the protons on the ortho and para positions of each ring would be more de-shielded than the signal for the meta protons due to the ring current effect. The ring current effect is the magnetic field created by the delocalization of π electrons in the aromatic ring.

The starting material for the synthesis of biphenyl is bromobenzene, which is a mono-substituted benzene. In the NMR spectrum of bromobenzene, there would be a single set of signals for the protons on the benzene ring. The signal for the proton on the ortho position would be more de-shielded than the signal for the meta protons, but the para protons would be the most shielded. This is because the bromine atom is an electron-withdrawing group, which deactivates the ring towards electrophilic substitution. Therefore, the proton on the para position is less likely to be substituted, making it the most shielded.

In conclusion, the difference in the aromatic region between the starting material and product is that the NMR spectrum of biphenyl would show two sets of signals, each representing the protons on each benzene ring, while the NMR spectrum of bromobenzene would show a single set of signals for the protons on the benzene ring. The NMR spectrum of biphenyl would integrate six hydrogen atoms.

know more about NMR spectrum,

https://brainly.com/question/30465398

#SPJ11

Predict the sign of the entropy change, ΔS∘, for each of the reaction displayed.
Drag the appropriate items to their respective bins:
Help
Reset
Ag+(aq)+Cl-(aq)→AgCl(s)
2KCIO3(s)+2KCI(s)+302(g)
2N2O(g) 2N2(g)+02(g)
2Mg(s)+O2(g)→2MgO(s)
C7H16(g)+1102(g)→7CO2(g)+8H2O(g)
H2O(1)→H2O(g)
Positive
Negative

Answers

The given reaction involves the evaporation of water. When water is heated, it evaporates into steam. The randomness and disorder increases as a result of the reaction. Therefore, the sign of reaction ΔS∘ is positive.

Entropy change, ΔS∘ is the difference between the entropy of the products and the entropy of the reactants. The entropy change, ΔS∘, for the given reactions can be predicted as follows:

Ag+(aq)+Cl-(aq)→AgCl(s):

The given reaction involves two aqueous ions forming a precipitate. Hence, the randomness and disorder decreases as a result of the reaction. Therefore, the sign of ΔS∘ is negative.

2KCIO3(s)+2KCI(s)+302(g):

The given reaction involves solid, aqueous, and gaseous states of matter. When potassium chlorate is heated, it decomposes into potassium chloride and oxygen gas. The randomness and disorder increases as a result of the reaction. Therefore, the sign of ΔS∘ is positive.

2N2O(g) 2N2(g)+02(g):

The given reaction involves two gases combining to form another gas. The randomness and disorder decreases as a result of the reaction. Therefore, the sign of ΔS∘ is negative.

2Mg(s)+O2(g)→2MgO(s):

The given reaction involves the reaction between a solid and a gas. When magnesium reacts with oxygen gas, magnesium oxide is formed. The randomness and disorder decreases as a result of the reaction. Therefore, the sign of ΔS∘ is negative.

C7H16(g)+1102(g)→7CO2(g)+8H2O(g):

The given reaction involves the combustion of heptane. When heptane burns, carbon dioxide and water are formed. The randomness and disorder increases as a result of the reaction. Therefore, the sign of ΔS∘ is positive.

H2O(1)→H2O(g):

The given reaction involves the evaporation of water. When water is heated, it evaporates into steam. The randomness and disorder increases as a result of the reaction. Therefore, the sign of ΔS∘ is positive.

To know more about Reaction ΔS∘ visit:

https://brainly.com/question/17418898

#SPJ11

What is the oxidation number of nitrogen in the nitrate ion NO31−?
a. +6
b. +5
c. +3
d. +2

Answers

The oxidation number of nitrogen in the nitrate ion (NO₃⁻) is +5. To determine the oxidation number, we assign a hypothetical charge to each element in the compound based on its electronegativity and known rules.

In NO₃⁻, oxygen is assigned an oxidation number of -2, since it typically exhibits a -2 charge in most compounds. Since there are three oxygen atoms in NO₃⁻, the total charge from the oxygen atoms is -6.

The overall charge of the nitrate ion is -1, so the sum of the oxidation numbers of all the atoms in the ion must equal -1. Therefore, to balance out the charge, nitrogen must have an oxidation number of +5.

We can calculate this by using the equation:

(+5) + (-6) = -1

Hence, the correct answer is b. +5.

Learn more about oxidation number here : brainly.com/question/29100691

#SPJ11

Calculate your % yield of CO2 in the reaction based on the grams of NaHCO3 being the limiting reagent in the reaction. .7656g NaHCO3 for Theoretical yield

Answers

The percent yield of CO₂ in the reaction based on the grams of NaHCO₃ is 93.3%.

Percent yield is use to assess the efficiency of a chemical reaction.    

To calculate percent yield is:                                                                

Percent yield = (Actual yield / Theoretical yield) × 100

Where,

Actual yield is the amount of product obtained from the reaction.

Theoretical yield is the maximum amount of product that could be obtained based on limiting reagent.

The equation of the reaction:

NaHCO₃  + CH₃ COOH ->CH₃ COONa +H₂O + CO₂

Moles of NaHCO₃ = 2.01/84 = 0.0239 moles

Theoretical yield of CO₂ = 0.0239 moles * 22.4 L/moles = 0.53536 = 0.536 L

Actual yield = 0.5 L

Percent yield = 0.50/0.536 * 100

= 93.3 %

Therefore, the percent yield is 93.3 %.

To learn more about Percent yield:

https://brainly.com/question/8638404

#SPJ4

The complete question is:

Calculate your % yield of CO₂ in the reaction based on the grams of NaHCO₃ being the limiting reagent in the reaction between 2.01 g of sodium bicarbonate and 24.6 mL of 1.5 acetic acid? They produce 0.50 L of at s.t.p.

Which substance is readily soluble in hexane (C6H14)?
A. H2O
B. PCl3
C. KOH
D. C3H8

Answers

The substance that is readily soluble in hexane (C₆H₁₄) is D. C₃H₈. Hence, option D is correct.

Hexane is a nonpolar solvent, and substances that are nonpolar or have similar nonpolar characteristics tend to be soluble in hexane. Among the given options, C₃H₈ (propane) is a nonpolar hydrocarbon and is, therefore, readily soluble in hexane.

A. H₂O (water) is a polar molecule and is not soluble in hexane.

B. PCl₃ (phosphorus trichloride) is a polar molecule and is not soluble in hexane.

C. KOH (potassium hydroxide) is an ionic compound and is not soluble in hexane.

Thus, the correct answer is D. C₃H₈. Hence, option D is correct.

Learn more about solubility from the link given below.

https://brainly.com/question/31493083

#SPJ4

Rank the following substances in order of decreasing standard molar entropy (S∘).
Rank the gases from largest to smallest standard molar entropy. To rank items as equivalent, overlap them.
Cl2(g) I2(g) F2(g) Br2(g)

Answers

The order of decreasing standard molar entropy is as follows: I₂(g) > Br₂(g) > Cl₂(g) > F₂(g)

A measure of a substance's degree of disorder or unpredictability under typical conditions is called standard molar entropy (S). It is influenced by things like molecular weight, molecular complexity, and the quantity of atoms in the molecule.

The following guidelines can be used in this situation to describe the order:

With increasing molar mass, the average entropy of molecules rises. With molar mass and structural complexity come increases in the conventional molar entropy. As structural complexity increases, the standard molar entropy rises.

We must order the gases from highest to lowest standard molar entropy in order to rank the following substances in decreasing order of standard molar entropy (S).

Thus, the order becomes- I₂(g) > Br₂(g) > Cl₂(g) > F₂(g)

This is due to the fact that the greater the molar mass, the larger the standard molar entropy.

To know more about standard molar entropy here https://brainly.com/question/29620266

#SPJ4

The ksp of yttrium fluoride, yf3, is 8. 62 × 10-21. Calculate the molar solubility of this compound

Answers

The molar solubility of yttrium fluoride (YF3) is 3.46 × 10-6 M.

The ksp of yttrium fluoride is 8.62 × 10-21. The molar solubility of this compound can be determined using the following formula:Ksp = [Y3+][F-]3We can set the molar solubility of yttrium fluoride as 'x'.

This is because the solubility of the yttrium fluoride will lead to the concentration of yttrium ions and fluoride ions. The Ksp expression for yttrium fluoride can be represented as follows:

Ksp = (x)(3x)3 = 27x4

where '3x' is the molar solubility of F-.

We can substitute Ksp value in the above expression and then solve for x:

8.62 × 10-21 = 27x4x = 3.46 × 10-6 M

Thus, the molar solubility of yttrium fluoride is 3.46 × 10-6 M.

To conclude, the molar solubility of yttrium fluoride (YF3) is 3.46 × 10-6 M.

To know more about molar solubility VISIT:

https://brainly.com/question/31043999

#SPJ11

Which regions of DNA are used for identification of different species? Select one: a. highly conserved b. highly variable c. positive controls d. primary 2. In PCR, what is used to separate the two DNA chains in the double helix? Select one: a. nucleotides b. high heat c. gel d. primers 3.Why is the sample heated to almost the boiling point in PCR? Select one: a. primers attach to DNA 4. What is special about the DNA polymerase used in PCR? Select one: a. denatures, or separates, DNA b. can withstand high temperatures c. attaches to either side of target DNA d. can withstand low temperatures b. new nucleotides attach to DNA strand c. the DNA denatures, or separates d. the DNA strands pair up 5. Name the apparatus that will heat and cool the PCR sample. Select one: a. DNA thermocycler b. automatic DNA sequencer c. PCR tubes d. buccal swab

Answers

The highly variable region of DNA is used for identification of different species. In PCR, high heat is used to separate the two DNA chains in the double helix.The sample is heated to almost the boiling point in PCR so that the DNA denatures or separates.The DNA polymerase used in PCR can withstand high temperatures.The apparatus that will heat and cool the PCR sample is called DNA thermocycler.

PCR stands for polymerase chain reaction. It is a technique used in molecular biology to amplify a single copy or a few copies of a segment of DNA across several orders of magnitude, creating millions or billions of copies of a particular DNA sequence. PCR is now a common and essential technique used in medical and biological research laboratories for a variety of applications.

Learn more about DNA polymerase here:

https://brainly.com/question/29585040

#SPJ11

This reaction is endothermic.
C(s)+CO2(g)=>2CO(g)
Predict the effect (shift right, shift left, or no effect) of increasing and decreasing the reaction temperature. How does the value of the equilibrium constant depend on temperature?

Answers

Increasing the reaction temperature will shift the reaction to the right, while decreasing the reaction temperature will shift the reaction to the left. Equilibrium constant (K) for the reaction is temperature-dependent.

Effect of increasing temperature:

In an endothermic reaction, increasing the temperature provides more energy to the system. According to Le Chatelier's principle, the system will respond by shifting the equilibrium in the direction that consumes heat, which is the forward reaction in this case (shift right). As a result, the concentration of CO and the overall yield of the reaction will increase.

Effect of decreasing temperature:

Decreasing the temperature reduces the energy available to the system. To compensate for the decrease in energy, the system will shift the equilibrium in the direction that releases heat, which is the reverse reaction in this case (shift left). Consequently, the concentration of CO2 and the overall yield of the reaction will increase.

Dependence of equilibrium constant on temperature:

The equilibrium constant (K) is a measure of the extent of the reaction at a given temperature. For an endothermic reaction, increasing the temperature favors the forward reaction, resulting in an increase in the value of K. Conversely, decreasing the temperature favors the reverse reaction and leads to a decrease in the value of K.

Increasing the reaction temperature shifts the equilibrium to the right, favoring the formation of CO. Decreasing the temperature shifts the equilibrium to the left, favoring the formation of CO2. The equilibrium constant (K) for the reaction is dependent on temperature and increases with an increase in temperature for an endothermic reaction.

To know more about Equilibrium, visit:

https://brainly.com/question/18849238

#SPJ11

The active ingredient in milk of magnesia is Mg(OH)2. Complete and balance the following equation. Mg(OH)2 + HCI →

Answers

The active ingredient in milk of magnesia is Mg[tex](0H)_{2}[/tex] . To complete and balance the equation

Mg[tex](0H)_{2}[/tex] + 2HCl → Mg[tex]Cl_{2}[/tex] + 2[tex]H_{2}[/tex]O

To complete and balance the equation

Mg[tex](0H)_{2}[/tex] + 2HCl → Mg[tex]Cl_{2}[/tex] + [tex]H_{2}[/tex]O

The balanced equation is

Mg[tex](0H)_{2}[/tex] + 2HCl → Mg[tex]Cl_{2}[/tex] + 2[tex]H_{2}[/tex]O

In this reaction, magnesium hydroxide (Mg[tex](0H)_{2}[/tex] ) reacts with hydrochloric acid (HCl) to form magnesium chloride (Mg[tex]Cl_{2}[/tex] ) and water

([tex]H_{2}[/tex]O).

To know more about milk of magnesia here

https://brainly.com/question/13570252

#SPJ4

Other Questions
This native of Houston, Texas, served as the Secretary of the Treasury (1985-1988)under Ronald Reagan, Secretary of state (1989-1992) under George H.W. Bush, andthe Chief of Staff for both Reagan (1981-1985) and G.H.W. Bush (1992-1992).A.) John GarnerB.) James BakerC.) Sul RossD.) Sam Houston How many protons are in nitrogen Please give me an accurate answer.Only answer if you're very good at History.Please don't put a link to a website.Do you think it is right to protect sites along "The Trails of Tears"?Yes or No and Why. Forensic investigator Adams is working on a crime scene involving the use of a very rare explosive. She already knows that she needs to find out who set the explosive. Following the scientific method what would be her next step in solving this mystery? Form a hypothesis about the person who bought the explosive Conclude that the homeowner set the explosive Collect some data about the distribution of the explosive Hand over her work to the police so that they can make an arrest if the yield curve is downward sloping, which of the following statements is correct? (hint: graph the yield curves for a t-bond, a aaa bond, and a b bond) Kristy owns a firm that produces cakes. The table shows the firm's total product schedule.If Kristy increases the number of workers employed from 3 to 4, what is the marginal product of labor?If she increases the number of workers employed from 4 to 5, what is the marginal product of labor?If Kristy increases the number of workers employed from 3 to 4, the marginal product of labor is _____ cakes an hour.If she increases the number of workers employed from 4 to 5, the marginal product of labor is _____ cakes an hour.Labor (worker) Output0 0 1 102 243 384 465 506 62 Element X decays radioactively with a half life of 11 minutes. If there are 870 gramsof Element X, how long, to the nearest tenth of a minute, would it take the element todecay to 154 grams?y = a(.5) t/h Question 8 7 pts is the following statement true or false? Explain your answer. An increase in income will lead to a rightward shift of the demand curve of normal product X, which increases the price Think of a team that you have been on. Reflect on the meetings/interactions/decisions that this team has made. Based on this team, answer the following questions:Where has your team experienced groupthink? Explain the situation.Of the 8 symptoms of groupthink identified in the online lecture video in week 3.1, which were present in your group? Which of these is an example of qualitative data? A how many books your classmates read this year B. your classmates' favorite books C. how much a book costs at the store D. how many pages your favorite book has Excerpt from Invisible Man by Ralph EllisonRead the passage and then select which two statements best describe a central idea in the passage?It goes a long way back, some twenty years. All my life I had been looking for something, and everywhere I turned someone tried to tell me what it was. I accepted their answers too, though they were often in contradiction and even self-contradictory. I was naive. I was looking for myself and asking everyone except myself questions which I, and only I, could answer. It took me a long time and much painful boomeranging of my expectations to achieve a realization everyone else appears to have been born with: That I am nobody but myself. But first I had to discover that I am an invisible man!And yet I am no freak of nature, nor of history. I was in the cards, other things having been equal (or unequal) eighty-five years ago. I am not ashamed of my grandparents for having been slaves. I am only ashamed of myself for having at one time been ashamed. About eighty-five years ago they were told that they were free, united with others of our country in everything pertaining to the common good, and, in everything social, separate like the fingers of the hand. And they believed it. They exulted in it. They stayed in their place, worked hard, and brought up my father to do the same. But my grandfather is the one. He was an odd old guy, my grandfather, and I am told I take after him. It was he who caused the trouble. On his deathbed he called my father to him and said, "Son, after I'm gone I want you to keep up the good fight. I never told you, but our life is a war and I have been a traitor all my born days, a spy in the enemy's country ever since I give up my gun back in the Reconstruction. Live with your head in the lion's mouth. I want you to overcome 'em with yeses, undermine 'em with grins, agree 'em to death and destruction, let 'em swoller you till they vomit or bust wide open." They thought the old man had gone out of his mind. He had been the meekest of men. The younger children were rushed from the room, the shades drawn and the flame of the lamp turned so low that it sputtered on the wick like the old man's breathing. "Learn it to the younguns," he whispered fiercely; then he died.But my folks were more alarmed over his last words than over his dying. It was as though he had not died at all, his words caused so much anxiety. I was warned emphatically to forget what he had said and, indeed, this is the first time it has been mentioned outside the family circle. It had a tremendous effect upon me, however. I could never be sure of what he meant. Grandfather had been a quiet old man who never made any trouble, yet on his deathbed he had called himself a traitor and a spy, and he had spoken of his meekness as a dangerous activity. It became a constant puzzle which lay unanswered in the back of my mind. And whenever things went well for me I remembered my grandfather and felt guilty and uncomfortable. It was as though I was carrying out his advice in spite of myself. And to make it worse, everyone loved me for it. I was praised by the most lily-white men of the town. I was considered an example of desirable conductjust as my grandfather had been. And what puzzled me was that the old man had defined it as treachery. When I was praised for my conduct I felt a guilt that in some way I was doing something that was really against the wishes of the white folks, that if they had understood they would have desired me to act just the opposite, that I should have been sulky and mean, and that that really would have been what they wanted, even though they were fooled and thought they wanted me to act as I did. It made me afraid that some day they would look upon me as a traitor and I would be lost. Still I was more afraid to act any other way because they didn't like that at all. The old man's words were like a curse.Which two statements best describe a central idea in the passage?Group of answer choicesthe importance of following the rules in order to fit into societythe barbaric nature of slaverythe struggle to find ones identitythe emptiness left behind by the loss of a loved onethe effects of the Civil War on the lives of African Americansthe complicated nature of race relations in the United States what is 7 8/9 written as a decimal true or false enthalpy is defined as the change in heat at constant pressure In 2021, Southwestern Corporation completed the treasury stock transactions listed below. February 2: Reacquired 60,000 shares at $11.00. March 17: Sold 10,000 shares at $13.50. May 17: Sold 15,000 shares at $7.50. Southwestern had issued 100,000 shares of its $1 par common stock for $10 several months ago. Required: Prepare the journal entries to record the above transactions, using the cost method. Tyrone is working with two other students to build a border around the schools triangular garden. Each student brought in one side of the border, but they all used different units to measure the side lengths. The first side is 312 inches long, the second side is 20 feet long, and the third side is 12 yards long. If the measurements need to be in feet, will the three border pieces make a right triangle?Convert the third side into feet using a proportion. What strategies should writers use to help organize their ideas for an informational essay?Select all that apply.A. Make an idea map.B. Make an outline.C. Create a research plan.D. Create a thesis statement. Match the correct term to its definition.Fomite E. Portal of exitVector F. ZoonoticReservoir G. Incubation periodPortal of entry34. _______ Site where infectious agent enters the body35. _______ Disease transmitted through an animal bite36. _______ Population or environment in which pathogen lives and reproduces and on which it depends on its survival37. _______ Inanimate object covered in disease-causing agent38. _______ Interval between exposure to pathogen and first signs and symptoms of disease39. _______ Site where infectious agent leaves the body40. _______ Living insect or animal involved with disease transmission HELP I NEED HELP ASAPHELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAPHELP I NEED HELP ASAPHELP I NEED HELP ASAP HELP I NEED HELP ASAP HELP I NEED HELP ASAP How many neutrons are in the nucleus of an atom with an atomic mass of 80 A.M.U. and an atomic number of 35? Solve the equation for solutions over the interval [0, 360). 7tan7/3cot=0