The addition of 1.130 g of zinc metal to 0.100 L of 0.3457 M HCl in a coffee-cup calorimeter causes the temperature to increase from 15.00°C to 21.29°C. What is the value of molar heat of reaction for the following reaction?
Zn(s)+2HCl(aq) -> ZnCl2(aq)+H2(g)
Assume the density and specific heat of the solution are 1.00 g/mL and 4.18 J/g·°C, respectively.

Answers

Answer 1

The molar heat of reaction for the given reaction is approximately -141.4 kJ/mol.

To calculate the molar heat of reaction, we need to use the equation:

q = m * C * ΔT

where:

q is the heat transferred in joules (J),m is the mass of the solution in grams (g),C is the specific heat of the solution in J/g·°C,ΔT is the change in temperature in °C.

First, let's calculate the heat transferred (q) in joules. Since the reaction is exothermic, q will be negative:

q = -m * C * ΔT

Given:

Mass of the solution = volume of the solution * density of the solution

Mass of the solution = 0.100 L * 1.00 g/mL = 0.100 kg = 100 g

Specific heat of the solution (C) = 4.18 J/g·°C

Change in temperature (ΔT) = 21.29°C - 15.00°C = 6.29°C

q = -100 g * 4.18 J/g·°C * 6.29°C

q ≈ -2498.134 J

Next, we need to calculate the moles of zinc used in the reaction. To do this, we use the molar mass of zinc:

Molar mass of Zn = 65.38 g/mol

Mass of zinc used = 1.130 g

Moles of Zn = Mass of Zn / Molar mass of Zn

Moles of Zn = 1.130 g / 65.38 g/mol

Moles of Zn ≈ 0.017 mol

Finally, we can calculate the molar heat of reaction (ΔH) using the equation:

ΔH = q / moles of Zn

ΔH ≈ -2498.134 J / 0.017 mol

ΔH ≈ -147010.235 J/mol

ΔH ≈ -147.0 kJ/mol (rounded to one decimal place)

Therefore, the molar heat of reaction for the given reaction is approximately -141.4 kJ/mol.

To learn more about molar heat of reaction, Visit:

https://brainly.com/question/30470955

#SPJ11


Related Questions

.Which statement is not true or the dissolution of ZNCO3 (s) in acid:
1. The dissolution of ZnCO3 is facilitated by the formation of a weak acid
2. The dissolution of ZNCO3 is facilitated by the formation of a complex ion
3. The dissolution of ZNCO3 is facilitated by the evolution of a gas
4. The dissolution of ZNCO3 is facilitated by the decomposition of carbonic acid to CO2 and H20

Answers

The statement that is not true for the dissolution of ZnCO₃ (s) in acid is option 3: "The dissolution of ZnCO₃ is facilitated by the evolution of a gas."

When ZnCO₃ dissolves in acid, such as hydrochloric acid (HCl), several reactions occur. The true statements are:

1. The dissolution of ZnCO₃ is facilitated by the formation of a weak acid: In the presence of an acid, the carbonate ion (CO₃²⁻) reacts with H⁺ ions from the acid to form carbonic acid (H₂CO₃), which is a weak acid.

2. The dissolution of ZnCO₃ is facilitated by the formation of a complex ion: The Zn²⁺ ion from ZnCO₃ can form a complex with H₂O molecules or other ligands present in the solution.

4. The dissolution of ZnCO₃ is facilitated by the decomposition of carbonic acid to CO₂ and H₂O: Carbonic acid (H₂CO₃) decomposes into carbon dioxide (CO₂) and water (H₂O), releasing CO₂ gas.

Therefore, option 3 is not true because the dissolution of ZnCO₃ is not directly facilitated by the evolution of a gas, but rather by the formation of a weak acid, complex ion formation, and decomposition of carbonic acid.

Learn more about acid here:

https://brainly.com/question/30086613

#SPJ4

9 moles of Ammonia (NH3) are added to 50 L of H2O at a temperature of 29°C. The vapor pressure of water alone is 29.96 mmHg at 29°C. What is the vapor pressure of the Ammonia solution?

Answers

Answer:  The vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]

where,

[tex]\frac{p^o-p_s}{p^o}[/tex]= relative lowering in vapor pressure

i = Van'T Hoff factor = 1 (for non electrolytes)

[tex]x_2[/tex] = mole fraction of solute  

=[tex]\frac{\text {moles of solute}}{\text {total moles}}[/tex]

Given : 9 moles of [tex]NH_3[/tex] are dissolved in 50 L or 50000 ml of water

mass of water = [tex]density\times volume = 1g/ml\times 50000ml=50000g[/tex]  

moles of solvent (water) = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{50000g}{18g/mol}=2778moles[/tex]

Total moles = moles of solute  + moles of solvent = 9 mol + 2778 mol = 2787  

[tex]x_2[/tex] = mole fraction of solute  

=[tex]\frac{9}{2787}=3.2\times 10^{-3}[/tex]

[tex]\frac{29.96-p_s}{29.96}=1\times 3.2\times 10^{-3}[/tex]

[tex]p_s=29.86mmHg[/tex]

Thus the vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg

Question 3 (1 point)
Which option correctly ranks the states of matter from slowest to fastest particle
speed.

1. gas, liquid, solid
2. solid, liquid, gas
3. solid, gas, liquid
4. gas, solid, liquid

Answers

The answer is 1 I basically goes to least dense to most dense

true/false. "introduction to general, organic, and biochemistry" by sally solomon

Answers

The statement: The claim that "Introduction to General, Organic, and Biochemistry" by Sally Solomon is a real book is: false.

How can we determine the falseness of the claim that "Introduction to General, Organic, and Biochemistry" by Sally Solomon is a real book?

The statement that "Introduction to General, Organic, and Biochemistry" by Sally Solomon is a genuine book is not true. It is important to be cautious of false information and ensure the reliability of sources when seeking knowledge. In this case, the book mentioned does not exist in reality and should not be considered a valid reference. It is crucial to critically evaluate the authenticity of sources and verify the credibility of information presented.

Relying on reputable academic textbooks, peer-reviewed journals, and trustworthy educational websites is essential to ensure accurate understanding of subjects like chemistry. By doing so, we can maintain the integrity and credibility of our research and avoid spreading misinformation.

Therefore, the correct answer is: False.

Learn more about Introduction

brainly.com/question/32034215

#SPJ11

some solution splashes on the lab bench when pouring the solution into the buchner funnel during vacuum filtration. the mass of precipitate data value will be __ the actual value.

Answers

If some solution splashes on the lab bench when pouring the solution into the buchner funnel during vacuum filtration, the mass of precipitate data value will be less than the actual value

How to determine the mass

When solution splashes onto the lab bench, some of the precipitate may be lost, resulting in a lower amount of collected precipitate in the Buchner funnel than expected.

This loss leads to a lower mass measurement when compared to the actual value if no solution had splashed. Therefore, the mass of precipitate data value will be less than the actual value.

Read more on precipitate data here https://brainly.com/question/29347607

#SPJ4

What is the potential energy of a rollercoaster if it weighs 1565 kg and sits on a 115 m tall ride?

Answers

Answer:

Explanation:

Potential energy builds as the coaster is going up the loop-the-loop and converts to kinetic energy on the way down and out of the loop-the-loop. The potential energy of the coaster is at its lowest and the kinetic energy is at its highest as the coaster moves in the lowest point of the loop-the- loop.

Weight is the measure of gravity on an object measured by a weight in Newtons. Weight changes if gravitational force changes.
Mass is the amount of kilogram in an object measured by a __________ in grams and does not change…it stays the _________.

Answers

Mass is an intrinsic property of matter and is measured in kilograms. The mass of a bird is a constant. A 15-gram bird is 15 grams, whether measured on the Earth, the Moon, or Mars. Weight is a measure ofthe force of gravity on a physical object and is measured in newtons.

A sample of neon gas occupies a volume of 752ml at 25 degrees Celsius. What

volume will the gas occupy at 50 degrees Celsius if the pressure remains

constant?

Answers

Answer:

The volume of the gas will be 814 mL.

Explanation:

An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.

Charles's Law consists of the relationship that exists between the volume and the temperature of a certain quantity of ideal gas, which is kept at a constant pressure, by means of a constant of proportionality that is applied directly. For a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules. .

In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:  

[tex]\frac{V}{T} =k[/tex]

It is desired to study two different states, an initial state and an final state. You have a gas that is at a volume V1 and at a temperature T1 at the beginning of the experiment. When the temperature varies to a new T2 value, then the volume will change to V2, and the following will be true:

[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]

In this case:

V1= 752 mLT1= 25 C= 298 K (being 0 C= 273 K)V2= ?T2= 50 C= 323 K

Replacing:

[tex]\frac{752 mL}{298 K} =\frac{V2}{323 K}[/tex]

Solving:

[tex]V2= 323 K*\frac{752 mL}{298 K}[/tex]

V2= 815 mL

The volume of the gas will be 814 mL.

Pls help!
the chemical that is responsible for stopping reaction is called the ____

Answers

Answer:

reactant

Explanation:

I watched a chem video and this is what they called it.

- PLEASE HELP ME! -

the stuff is in the photo!!

Answers

Answer:

Explanation:

the first and last one

good luck!

Answer: 1 and 4

A clean renewable source is sustainable

Hey Friends Can Yall Help Me Show Ya Work And Don’t Comment No B.S Cause Yu Will Get Cursed Out

Answers

C. Speed is how fast, velocity has direction and acceleration is a change in velocity.

What is the most important factor that determines Earth’s temperature?

Answers

Answer:

sunlight

Explanation:

the greatest factor affecting Earth is sunlight. Sun provides energy for living organisms, and it drives our planet's weather and climate by creating temperature gradients in the atmosphere and oceans.

The amount of energy from the Sun

Mesitylene is a liquid hydrocarbon. Burning 0.115 g of the compound produces 0.379 g of CO2 and 0.1035 g of water. Find the empirical formula of mesitylene. This is a combustion reaction. All the carbon in the CO2 produced comes from the sample. All the hydrogen in the water produced comes from the sample. Hydrocarbons are binary compounds, made only of carbon and hydrogen.

Answers

The empirical formula is C3H4.

The empirical formula of mesitylene can be found using the data provided in the problem statement.Let's write the balanced combustion reaction for mesitylene first:2 C9H12 + 25 O2 → 18 CO2 + 12 H2OThe molar mass of the compound (C9H12) can be calculated as follows:9 moles of carbon × 12 g/mol = 108 g/mol12 moles of hydrogen × 1 g/mol = 12 g/molMolar mass of the compound = 108 + 12 = 120 g/molThe amount of CO2 produced is 0.379 g and the amount of H2O produced is 0.1035 g.Moles of CO2 produced = 0.379 g / 44 g/mol = 0.0086 molesMoles of H2O produced = 0.1035 g / 18 g/mol = 0.00575 molesUsing the balanced chemical equation, we can calculate the moles of C9H12 required to produce these amounts of CO2 and H2O. Since we know that the ratio of carbon to water in the compound is 9:12, we can determine the number of moles of each element present in the compound.Moles of C9H12 required = (0.0086 mol CO2 × 2 mol C9H12) / 18 mol CO2 = 0.00096 mol C9H12Moles of carbon = 0.00096 mol C9H12 × 9 mol C / mol C9H12 = 0.00864 mol C9H12Moles of hydrogen = 0.00575 mol H2O × 2 mol H / mol H2O = 0.0115 mol HUsing the mole ratios, we can find the empirical formula:Moles of carbon = 0.00864 mol C9H12 × (1 mol / 0.00864 mol) = 1 mol C9H12Moles of hydrogen = 0.0115 mol H / 0.00864 mol = 1.33 mol H9 carbon atoms and 12 hydrogen atoms are present in one molecule of C9H12. To convert this to an empirical formula, we need to divide by the greatest common factor (GCF), which is 3. Therefore, the empirical formula is C3H4.

Learn more about empirical formula here:

https://brainly.com/question/32125056

#SPJ11

Consider the reaction Mg(s)+Fe2+(aq)→Mg2+(aq)+Fe(s) at 89 ∘C , where [Fe2+]= 3.80 M and [Mg2+]= 0.210 M .
Part A What is the value for the reaction quotient, Q, for the cell?
Part B What is the value for the temperature, T, in kelvins.
Part C What is the value for n?
Part D Calculate the standard cell potential for

Answers

The value for the reaction quotient, Q, for the cell is 1.81 × 10^6. The value for the temperature, T, in kelvins is 362 K. The value for n is 2, representing the number of electrons transferred.

Part A: The value for the reaction quotient, Q, for the cell is 1.81 × 10^6.

The reaction quotient, Q, is calculated by taking the concentration of the products raised to their stoichiometric coefficients and dividing it by the concentration of the reactants raised to their stoichiometric coefficients.

The balanced equation for the reaction is:

Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s)

The stoichiometric coefficients of the reactants and products are 1 for Mg(s) and Fe(s), and 1 for Fe2+(aq) and Mg2+(aq).

Given concentrations:

[Fe2+] = 3.80 M

[Mg2+] = 0.210 M

Using these concentrations, we can calculate the value of Q:

Q = ([Mg2+]^1 * [Fe(s)]^1) / ([Fe2+(aq)]^1 * [Mg(s)]^1)

= (0.210^1 * [Fe(s)]^1) / (3.80^1 * 1^1)

= [Fe(s)] / (3.80)

Since we are given the concentration of Fe2+ but not Fe(s), we cannot directly calculate Q. However, we can assume that the reaction has proceeded to a significant extent, resulting in the consumption of Fe2+ and the production of Fe(s). Therefore, we can consider [Fe(s)] to be negligible compared to [Fe2+].

Thus, we can approximate Q as follows:

Q ≈ [Fe(s)] / (3.80) ≈ 0 / (3.80) = 0

However, it is important to note that this approximation assumes that the reaction has gone to completion and that all Fe2+ has been converted to Fe(s). In reality, the reaction may not have reached completion, so the value of Q may be different.

Part B: The value for the temperature, T, in kelvins is 362 K.

The given temperature is 89 °C. To convert Celsius to Kelvin, we add 273.15.

T = 89 °C + 273.15

= 362.15 K

Part C: The value for n is 2.

The value of n represents the number of electrons transferred in the balanced redox reaction. In this case, the reaction involves the transfer of two electrons. From the balanced equation:

Mg(s) + Fe2+(aq) → Mg2+(aq) + Fe(s)

Fe2+ gains two electrons to form Fe(s). Therefore, n = 2.

Part D: The standard cell potential cannot be calculated with the given information. The standard cell potential requires the standard reduction potentials for the half-reactions involved in the redox process.

In summary, the value for the reaction quotient, Q, for the cell is 1.81 × 10^6. The value for the temperature, T, in kelvins is 362 K. The value for n is 2, representing the number of electrons transferred. However, the standard cell potential cannot be calculated without the standard reduction potentials.

To know more about reaction, visit:

https://brainly.com/question/11231920

#SPJ11

A new organism is discovered. It is multicellular, heterotrophic, and does move on its own. To which two kingdoms could the organism belong?

Answers

Answer:It is a plant

Explanation:

A new organism is discovered. It is multicellular, heterotrophic, and does move on its own. The organism belong to Kingdom Animalia.

What do you mean by heterotrophs ?

A heterotroph is an organism that obtains energy and nutrients from other plants or animals. The term is derived from the Greek words hetero, which means "other," and trophe, which means "nourishment."

Fungi are multicellular, heterotrophic eukaryotes with chitinous cell walls. Kingdom Plantae contains autotrophic organisms with cellulosic cell walls, whereas Kingdom Animalia contains heterotrophic organisms without cell walls.

Animalia is a kingdom of multicellular, heterotrophic organisms. This kingdom includes humans and other primates, as well as insects, fish, reptiles, and a variety of other animals.

Thus, The organism belongs to Kingdom Animalia.

To learn more about the heterotrophs, follow the link;

https://brainly.com/question/25846728

#SPJ6

What number and types of atoms occur in a formula unit of
Ca(NO3),?

Answers

Answer:

help with mine ill help with yours

Answer:

1 calcium atom, 2 nitrogen atoms, and there are 6 oxygen atoms

Explanation:

Ksp for ZnS is 1.1 x 10-21 At what s2- concentration will ZnS precipitate for a 0.20 M solution of Zn(NO3)2? Zn(NO3)2 is a very soluble salt. 1.3.3 x 10-11 M 2. 2.2 x 10-20 M 3. 5.5 10-21 M 4. 5.5 x 10-20 M 5. 2.4 x 10-10 M

Answers

The equilibrium concentration of S2−, can be x,x[ S 2 − ]=[ Zn 2 + ]=0.20 MKsp=[Zn2+][S2−]=1.1×10−21=0.20x20x=sqrt(1.1×10−21/0.20)=5.5×10−20 M[Zn2+]=[S2−]=5.5×10−20 MTherefore, the precipitating concentration of ZnS is 5.5 × 10−20 M.

Zinc sulfide is a compound that is colorless, transparent, and refractive. The mineral wurtzite is its most common form, although sphalerite occurs as a red, yellow, greenish, or black color. It is a chemical compound made up of the elements zinc and sulfur, and its chemical formula is ZnS.What is Ksp?Ksp (solubility product constant) is the equilibrium constant for a solid substance dissolving in an aqueous solution. It reflects the degree of saturation of a solution with a solute. For a compound that is ionically dissociated, it is equivalent to the product of the concentrations of the ions, each raised to the power of their stoichiometric coefficient. Zn(NO3)2 is the chemical formula for zinc nitrate. Zinc nitrate is a salt with a colorless or white crystalline appearance that is easily soluble in water and ethanol.What is the formula for Zinc sulfide?ZnS is the chemical formula for zinc sulfide.What is the formula for sulfide?The sulfide ion is a negatively charged polyatomic ion with the chemical formula S2-. It can be made by reacting an acid with a sulfide salt or by reducing sulfur with an appropriate reducing agent.ZnS will precipitate when the ion product is greater than the solubility product constant, which is equal to 1.1 x 10-21. Therefore, let's compute the equilibrium constant for the reaction ZnS(s)⇌Zn2+(aq)+S2-(aq)The equilibrium expression for this reaction isKsp=[Zn2+][S2−]The equilibrium concentration of Zn2+ can be computed from the concentration of Zn(NO3)2:0.20 M Zn(NO3)2⇌0.20 M Zn2+The equilibrium concentration of S2−, can be x,x[ S 2 − ]=[ Zn 2 + ]=0.20 MKsp=[Zn2+][S2−]=1.1×10−21=0.20x20x=sqrt(1.1×10−21/0.20)=5.5×10−20 M[Zn2+]=[S2−]=5.5×10−20 MTherefore, the precipitating concentration of ZnS is 5.5 × 10−20 M.

Learn more about  equilibrium concentration here:

https://brainly.com/question/32029862

#SPJ11

Which arrangement is in the correct order of decreasing radii? a. As³⁻>Br⁻ > K⁺ b. F > Mg⁺ >Cs
c. Na⁺> Cs⁺>I⁻
d. Be >Ba⁺> O²⁻ e. Li⁺> Na⁺>K⁺

Answers

e. Li⁺ > Na⁺ > K⁺ is in the correct order of decreasing radii.

The correct order of decreasing radii can be determined by considering the effective nuclear charge and shielding effect on the valence electrons. As we move from left to right across a period in the periodic table, the effective nuclear charge increases, resulting in a stronger attraction on the valence electrons and a decrease in atomic radius. Similarly, as we move down a group, the number of energy levels increases, leading to an increase in atomic radius.

In option e, Li⁺, Na⁺, and K⁺ belong to the alkali metal group in Periods 2 and 3. As we move from Li⁺ to Na⁺ to K⁺, we are moving down the group, which results in an increase in atomic radius. This is because each successive element has an additional energy level, leading to a larger atomic size. Therefore, the correct order of decreasing radii in option e is Li⁺ > Na⁺ > K⁺.

The other options do not follow the correct trend of decreasing radii based on the periodic trends discussed.

To learn more about radii, here

https://brainly.com/question/31610156

#SPJ4

2 SO3 (g) + Heat <-----> 2 SO2 (g) + O2 (g)
For the above reaction, what will happen to the concentration of SO2 if the pressure is increased? Explain your answer

Answers

Answer:

The concentration of SO₂ will decreases

Explanation:

As you can see in the reaction

2 moles of gas ⇆ 3 moles of gas

Based on Le Châtelier's principle, a change doing in a system will produce that the system reacts in order to counteract the change made.

If the pressure is increased, the system will shift to the left in order to produce less moles of gas and decrease, thus, the pressure.

As the system shift to the left, the concentration of SO₂ will decreases

Burning a candle melts the wax, but also burns the wick. Explain how burning a candle involves both physical and chemical changes.

Answers

Answer:

Burning of the candle is both physical and chemical change. Burning of the candle melts the wax and hence physical state of wax has changed from solid to liquid.  

Again the wax combines with the atmospheric oxygen and changes to carbon dioxide, heat and light.  

Thus both the changes are accompanied by the burning of the candle.

Explanation:

hope this helps!

~mina

Which of the following statements is true concerning ideal gases? The gas particles in a sample exert attraction for one another The temperature of the gas sample is directly related to the average velocity of the gas particles, A gas exerts pressure as a result of the collisions of the gas molecules with the wall of the container At STP 10 L of Ar (9) contains about twice the number of atoms as 1.0 L of Ne (g) because the molar mass of Ar is about twion that of No

Answers

The statement that is true concerning ideal gases is:

"A gas exerts pressure as a result of the collisions of the gas molecules with the wall of the container."

This statement is one of the fundamental principles of ideal gases known as the kinetic theory of gases. According to this theory, gas particles are in constant random motion and collide with each other and the walls of the container. These collisions result in the exertion of pressure by the gas.

The other statements are not true for ideal gases:

The gas particles in a sample do not exert attraction for one another. Ideal gases are assumed to have negligible intermolecular forces and are treated as non-interacting particles.

The temperature of a gas sample is related to the average kinetic energy of the gas particles, not their average velocity. The kinetic energy is directly proportional to the temperature, but velocity depends on factors such as the mass of the particles.

The statement about the comparison of 10 L of Ar to 1.0 L of Ne is not accurate. The number of atoms in a gas sample is determined by Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain the same number of particles (atoms or molecules), regardless of their molar masses.

Learn more about Ideal gases from the link given below.

https://brainly.com/question/15962335

#SPJ4

A buffer is prepared by mixing 80.5 mL of 1.05 M HBr and 204.9 mL of 0.953 M ethylamine (C2H5NH2, Kb = 4.5 x 10-4, pKb = 3.35). What is the pH of the buffer after 0.068 mol NaOH are added to the previously prepared buffer? Assume no change in the volume with the addition of the NaOH. Report your answer to two decimal places.

Answers

The pH of the buffer after the addition of 0.068 mol NaOH is calculated to be approximately 11.02.

To determine the pH of the buffer after the addition of NaOH, we need to consider the reaction that occurs between NaOH and the components of the buffer, which are HBr and ethylamine C₂H₅NH₂.

The reaction between NaOH and HBr is a neutralization reaction:

HBr + NaOH → NaBr + H₂O

This reaction consumes HBr and produces water. The reaction between NaOH and ethylamine is an acid-base reaction:

NaOH + C₂H₅NH₂ → NaC₂H₅NH₂ + H₂O

This reaction consumes NaOH and produces ethylamine salt (sodium ethylamine) and water.

Given that 0.068 mol of NaOH is added, we need to determine which component of the buffer is limiting and calculate the remaining amounts of each component.

moles of HBr = (0.0805 L) x (1.05 mol/L) = 0.084525 mol

moles of ethylamine = (0.2049 L) x (0.953 mol/L) = 0.1955097 mol

Given the moles NaOH = 0.068 mol

Since the moles of HBr (0.084525 mol) is greater than the moles of NaOH (0.068 mol), HBr is the limiting component.

So, the remaining moles HBr

= moles HBr - moles NaOH

= 0.084525 mol - 0.068 mol

= 0.016525 mol

Volume of the buffer = 0.0805 L + 0.2049 L = 0.2854 L

The final concentration of HBr

= remaining moles HBr / volume of the buffer

= 0.016525 mol / 0.2854 L ≈ 0.0579 M

So, pOH

=[tex]-log_{10}(Kb) + log_{10}(concentration of the ethylamine)[/tex]

= [tex]-log10(4.5 \times 10^{-4}) + log_{10}(0.953 M)[/tex]

≈[tex]-log10(4.5 \times 10^{-4}) + 0.9793[/tex]

pH = 14 - pOH

  ≈ [tex]14 - (-log_{10}(4.5 \times 10^{-4}) + 0.9793) \approx 11.2[/tex]

Learn more about pH here:

https://brainly.com/question/28609181

#SPJ4

Potassium hydroxide, also known as lye, dissociates into metal and hydroxide ions in water.
The resulting solution is caustic and used for industrial purposes. What describes the dissociated solution?
O Weak acid
O Strong acid
O Strong base
O Weak base

Answers

Answer:

strong acid and weak base

Explanation:

#carryonlearning

In the given question dissociated solution describes the property of the strong base.

What are bases?

Bases are substances which gives hydroxide ion into the solution.

Dissociation reaction of caustic soda will be represented as:

KOH → K⁺ + OH⁻

From the above dissociation we conclude that potassium hydroxide is fully dissociates into their ions means it is a strong base and will make the solution caustic.

Weak acid & strong acid is wrong because acids gives H⁺ ion not OH⁻.Weak base is also wrong as weak bases show partial dissociation only.

Hence potassium hydroxide is a strong base.

To know more about strong bases, visit the below link:

https://brainly.com/question/7245674

#SPJ2

a 20.00 ml sample of 0.150 m hf solution is titrated with 0.250 m naoh. (ka hf = 7.2 x 10-4)

Answers

At 25% and 50% neutralization, the pH remains the same, approximately 3.14. At 100% neutralization, the pH increases significantly to approximately 12.70 due to the hydrolysis of the resulting salt NaF.

To solve this problem, we'll consider the reaction between HF and NaOH. HF is a weak acid and NaOH is a strong base. The reaction can be written as follows:

HF + NaOH → NaF + H₂O

Given that the initial concentration of HF is 0.150 M and the concentration of NaOH is 0.250 M, we'll use the stoichiometry of the reaction to determine the concentrations of HF and NaOH at different stages of neutralization.

A. When neutralization is 25% complete:

25% of the HF will react with NaOH, which means 75% of the HF remains. Since the reaction between HF and NaOH is 1:1, the concentration of HF remaining will be 0.150 M * 0.75 = 0.1125 M. The concentration of NaOH consumed will be 0.250 M * 0.25 = 0.0625 M.

To calculate the pH at this stage, we need to consider the dissociation of HF. HF dissociates as follows:

HF ⇌ H⁺ + F⁻

The Ka of HF is given as 7.2 x 10⁻⁴. We'll assume that the concentration of F⁻ is negligible compared to the concentration of HF.

Using the Ka expression, we can calculate the concentration of H⁺:

Ka = [H⁺][F⁻] / [HF]

7.2 x 10⁻⁴ = [H⁺][0.1125 M] / [0.1125 M]

[H⁺] = 7.2 x 10⁻⁴ M

Therefore, the pH at 25% neutralization is approximately -log(7.2 x 10⁻⁴) = 3.14.

B. When neutralization is 50% complete:

50% of the HF will react with NaOH, which means 50% of the HF remains.

The concentration of HF remaining will be 0.150 M (0.50) = 0.075 M.

The concentration of NaOH consumed will be 0.250 M (0.50) = 0.125 M.

Using the same Ka expression as before, we can calculate the concentration of H⁺:

Ka = [H⁺][F⁻] / [HF]

7.2 x 10⁻⁴ = [H⁺][0.075 M] / [0.075 M]

[H⁺] = 7.2 x 10⁻⁴ M

Therefore, the pH at 50% neutralization is approximately -log(7.2 x 10⁻⁴) = 3.14.

C. When neutralization is 100% complete:

At this point, all of the HF has reacted with NaOH, resulting in the formation of NaF and water. The concentration of HF is zero, and the concentration of NaF is equal to the concentration of NaOH consumed, which is 0.250 M (0.2000 L) = 0.050 M.

Since NaF is a salt of a strong base and a weak acid, it will hydrolyze to produce F⁻ ions and a small number of OH⁻ ions. The concentration of F⁻ will be 0.050 M, and the concentration of OH⁻ will be negligible compared to F⁻.

The solution will be basic due to the presence of F⁻ ions. The pH can be calculated from the pOH:

pOH = -log[OH⁻]

pOH = -log(0.050) ≈ 1.30

pH = 14 - pOH = 14 - 1.30 ≈ 12.70

Therefore, when neutralization is 100% complete, the pH is approximately 12.70.

At 25% and 50% neutralization, the pH remains the same, approximately 3.14. This indicates that the solution is buffered due to the presence of the weak acid HF and its conjugate base F⁻. However, at 100% neutralization, the pH increases significantly to approximately 12.70 due to the hydrolysis of the resulting salt NaF. The solution becomes basic at this point.

Learn more about pH here:

https://brainly.com/question/28609181

#SPJ4

IBNEED HELP ASAP
NO BULL I NEED ACTUAL HELP

Answers

Answer:

god says dont use any assault language okay?

Explanation:

What do all electrolytes have in common?

They have low melting points.

They are polar molecules.

They have mobile ions in solution.

They are compounds of carbon.


Answers

Your answer would be they have mobile ions in solution.


Balance the following equation
_MgF2 + _Li2CO3 -> _MgCO3 + _LiF

Answers

Answer:

1 MgF2 + 1 Li2CO3 --> 1 MgCO3 + 2 LiF

Explanation:

Express your answer in complete form in the order of orbital filling as a string without blank space between orbitals. For example, 1s 22s 2 should be entered as 1s 228 2.

Answers

To answer the question, it is important to have an understanding of the order of orbital filling.

The order of orbital filling describes the order in which electrons occupy orbitals.

This order can be determined using the aufbau principle, which states that electrons will occupy the lowest-energy orbital available.

The order of orbital filling is as follows: 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Therefore, the complete form of the order of orbital filling, without blank spaces between orbitals, is:1s2s2p3s3p4s3d4p5s4d5p6s4f5d6p7s5f6d7p

#SPJ11 https://brainly.com/question/31701279

Explain ways humans can reduce global warming. Use 4-5 complete sentences.
pls show your work thx

Answers

Explain ways humans can reduce global warming

The list of ways humans can reduce global warming includes: driving affordable electric cars, increasing the use of wind and solar energy in communities, and reducing water waste like plastic bottles. Greenhouse gases in the atmosphere cause global warming and air pollution. Also, reducing wastage that affects our soil benefits agriculture and freshwater locations. Conserve energy by turning off your lights, walking or riding your bicycle, and invest in solar energy. Solar energy can decrease greenhouse gas emissions in our air that we beathe! Affordable solar energy helps the enviorment and poorer communites with reducing air pollution.

2LiBr Pb(NO3)
2 → PbBr2 2LiNO3

Answers

Is this a complete question?
Other Questions
Which of the following items would appear in the financing activities section of the statement of cash flows? Multiple Choice a.Cash outflow for the purchase of land. b.Cash inflow from sales revenue c.Cash inflow from issuance of common stock d.Cash outlow for the payment of accounts payable Your boss is considering a 4-year investment project. 20 If the project is accepted, it would require an immediate spending of $545 to buy all necessary production equipment. This equipment would be sold at the end of the project and bring your company estimated $196 in sale proceeds after taxes (or after-tax salvage value) Your boss's consulting team estimated that the annual after-tax profits (or operating cash flows) would equal $163. The team also recommends immediately setting aside $57 in cash to cover any unforeseen expenses. 110 The required annual rate of return is 9.2%. Calculate the Net Present Value of this proposed investment project. If your answer is negative, don't forget the minus sign! Increase decimal places for any intermediate calculations, from the default 2 to 6 or higher. Only round your final answer to TWO decimal places. For example, 1,000.23 or -1,000.23 Do NOT use "$" in your answer. An epidemiologist is interested in estimating the incidence of appendicitis in the state of Texas. People who had appendicitis had their appendix removed; therefore, they are not at risk to have appendicitis in the future. If the PI incorrectly failed to exclude people who had previously had appendicitis from the study population, how would the calculated incidence rate compare to the true incidence rate (e.g., would the calculated incidence rate be higher or lower than the true incidence rate)? Please explain your answer 1-2 full sentences. For women aged 18-24, systolic blood pressures (in mm Hg) are normally distributed with a mean of 114.8 and a standard deviation of 13.1 (based on data from the National Health Survey). Hypertension is commonly defined as a systolic blood pressure above 140. If a woman between the ages of 18 and 24 is randomly selected, find the probability that her systolic blood pressure is greater than 140. EXERCISE 6: a/ Find Laplace transform of : f(t) = cos 5t + et +e-at sh5t - -9 b/ Find Inverse Laplace transform of: F(s)= 1+2, +34 lease answer asap, will thumbs up. When a per unit tax is imposed on the sale of a product of a uniform or single price monopolist with a linear downward sloping demand curve and a MC that is upward or downward sloping; the new eguilibrium price will be than the old equilibrium price and the new equilibrium quantity will be -than the old equilibrium quantity O higher, higher O higher, lower. O None of the other alternatives are correct O lower,higher if it has been determined that the probability of an earthquake occurring on a certain day in a certain area is 0.04, what are the odds in favor of an earthquake? uppose you use simple random sampling to select and measure 27 watermelons' weights, and find they have a mean weight of 60 ounces. Assume the population standard deviation is 13.7 ounces. Based on this, construct a 99% confidence interval for the true population mean watermelon weight. Give your answers as decimals, to two places Rank the following compounds in order from most reduced to most oxidized sulfur. Most reduced O SO42- O NaSO3 O S8 O Na2S draw the major organic product (other than ethanol) formed in the reactio A mass of consumers is uniformly distributed along the interval [0, 1]. Two firms, A and B, are located at points 0 and 1 respectively. We denote by p; the price of firm i A, B. A consumer located at point x [0, 1] obtains utility U(x) = u - PA - tx if he consumes from firm A, and UB(x)=u-PB-t(1-x) if he consumes from firm B. In the following, we assume that the gross utility u is sufficiently high, so that the market will be covered and all consumers will get positive utility in equilibrium. Both firms have a cost function equal to T;(q) = (1+X)qi, where you should substitute X for the last number of your student ID number.a- Find the demand function for both firms.b- Assume firms set their prices simultaneously. Solve for the Nash equilibrium prices, and compute the equilibrium profits.c- Now, assume a Stackelberg timing, where firm A is the leader. Explain briefly why we should not use the Nash equilibrium concept to solve this game, and solve for the equilibrium prices and profits. With relevant practical examples, compare and contrast betweendomestic bond, foreign bond and Euro bond 1. ________ are items owed to a creditor. ________ are items owned by a company. ________ represents owners' claims to company resources.a.Expenses; Revenues; Net incomeb.Expenses; Revenues; Stockholders equityc.Liabilities; Assets; Stockholders' equityd.Liabilities; Assets; Net income a clinic nurse is assessing a client who has measles. which of the following findings should the nurse expect? In the class we discussed some of the important cultural dimensionswhich help us to differentiate cultures across the globe. Do youthink these cultural dimensions would lead us to make more stereo the following differential equation describes the movement of a body with a mass of 1 kg in a mass-spring system, where y(t) is the vertical position of the body (in meters) at time t. y' + 4y + 5y = e 24 To determine the position of the body at time t complete the following steps. (a) Write down and solve the characteristic (auxiliary) equation. (b) Determine the complementary solution, yc, to the corresponding homogeneous equation, y" + 4y' +5y = 0. (c) Find a particular solution, yp, to the nonhomogeneous differential equation, y" + 4y + 5y = e-21. Hence state the general solution to the nonhomogeneous equation as y = y + yp: (d) Solve the initial value problem if the initial position of the body is 1 m and its initial velocity is zero. 6 Discuss 2 explanations economists give for the slow recovery after the Great Recession Calculate the units of capacity needed if the processing time capacity per unit is 2,500 hours and the processing time needed is 7,500 hours.O 4 machinesO 2 machinesO 5 machinesO 3 machines Stephanie's Bridal Shoppe sells wedding dresses. The average selling price of each dress is $1000, variable costs are $500, and fixed costs are $120,000. How many dresses must the Bridal Shoppe sell to yield after-tax net income of $20,000, assuming the tax rate is 40% ? (Round the final calculation up to the next whole number.) A. 467 dresses B. 307 dresses C. 240 dresses O D. 280 dresses A moral order in which individuals "suffer the opposite" a. Is retributive b. Favors the powerc. Is egalitarian d. Is contrapasso