(5 pts) Calculating Heat from Thermochemical Equations
The thermochemical equation for the combustion of methane gas is:

Calculate much heat is released when 3.5 moles of methane gas undergo a combustion reaction.

42.4 ml is the volume in milliliters of the lead ball if a lead ball is added to a graduated cylinder containing 50.6 ml of water.

A tall narrow container with a volume scale is used especially for measuring liquids.

The graduated cylinder contains water

mL is a volume unit.

Water volume = 50.6 ml

The lead ball caused an increase in volume from 50.6 ml to 93.0 mL.

The new volume is the lead ball volume plus the original water volume :

Final volume = Vlead ball+ Water original volume

[tex]93.0 mL= V_(lead ball) +50.6 ml[/tex]

[tex]V_(lead ball) = 93.0 mL - 50.6 ml[/tex]

[tex]V_(lead ball) = 42.4 ml[/tex]

Hence, 42.4 ml is the volume in milliliters of the lead ball.

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The number of grams present in 0.025 mole of Demerol hydrochloride is 7.094 grams.

It is a drug used in treating severe or moderate pain.

The moles are given = 0.025

The formula is C₁₅H₂₂CINO₂

The elements that present are C, H, Cl, N, O.

The molecular weight are given:

Carbon: 12.0107

Hydrogen: 1.00784

Chlorine: 35.453

Nitrogen: 14.007

Oxygen: 15.999

Multiply the molecular weight with moles and add them

(15 x 12.0107) + (22 x 1.00784) + (1 x 35.453) + (1 x 14.007) + (2 x 15.999) = 283.79098 grams per mole.

Now, multiply the number of moles given with the total molecular weight

283.79098 x 0.025 = 7.094

Thus, the number of grams are 7.094.

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The new planet is suitable for human life because it is similar to planet earth.

The new planet has similar atmosphere just like the earth's atmosphere. It has large amount of vegetation that can hold large amount of animals. It is suitable for growing for different crops that provide food to humans.

So we can conclude that the new planet is suitable for human life because it is similar to planet earth.

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If you fill the capillary tube all the way to the top, it will become difficult to obtain a sharp melting point.

The melting point of a solid is the temperature at which a solid is changed into a liquid upon application of heat.

If you fill the capillary tube all the way to the top, it will become difficult to obtain a sharp melting point thus it should be filled only  to about 2 - 3 mm.

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The correct statement regarding the specific heat capacity of the substance is as follows: air requires the most energy to increase its temperature followed by aluminum and then iron.

Specific heat capacity of a substance refers to the amount of thermal energy required to raise the temperature of a system by one temperature unit (1°C or 1K) without any change of phase.

According to this question, the specific heat of different elements are as follows:

Therefore, it can be said that air requires the most energy to increase its temperature followed by aluminum and then iron.

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Answer:

224.1105 grams is the answer

Answer:

1.67 moles Al₂O₃

Explanation:

To find the amount of aluminum oxide produced, you need to start with 5 moles FeO and multiply it by the mole-to-mole ratio displaying the relationship between moles FeO and moles Al₂O₃. This ratio incorporates the coefficients from the equation. Remember, make sure to write the ratio in a way that allows for the cancellation of moles FeO.

2 Al + 3 FeO ---> 3 Fe + 1 Al₂O₃

5 moles FeO          1 mole Al₂O₃
--------------------  x  ----------------------  = 1.67 moles Al₂O₃
                              3 moles FeO

Suppose that 0.25M IBr in a flask,  the Kc at the given temperature is mathematically given as

Kc=0.00336814413

Generally, the equation for Chemical Reaction is mathematically given as

2IBr--->T2+8r_2

Therefore

K={I2*Br2}/IBR^2

K=x^2/(0.25-2x)^2

Kc=0.13M^2/0.224M^2

Kc=0.00336814413

In conclusion,  the Kc at the given temperature

Kc=0.00336814413

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The mass of water in the tank, given the data from the question is 549594 g

The mole of a substance is related to it's mass and molar mass according to the following equation:

Mole = mass / molar mass

From the question given above, the following data were obtained:

The mass of the water can be obtained as follow:

Mass = mole × molar mass

Mass of water = 30533 × 18

Mass of water = 549594 g

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If you add 25 g of CaCl2 to 1000. mL of water, what concentration of the solution would be 0. 225 grams/liter

Molarity or molar concentration(M) is defined as the  amount of a substance in a given volume of solution.

It is also known as the moles of a solute in a liter of  the solution.

Formula:

Concentration or molarity = number of moles ÷ volume

The number of moles is derived thus;

Number of moles = mass ÷ molar mass

mass of CaCl2 = 25g and molar mass = 110. 98 g/mol

Number of moles = 25 ÷ 110. 98 = 0. 225 mol

Given the volume = 1000 ml = 1 liter

Concentration = 0.225 ÷ 1 = 0. 225 grams/liter

Therefore, If you add 25 g of CaCl2 to 1000. mL of water, the concentration of the solution would be 0. 225 grams/liter

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Answer:

A noble gas configuration of an atom consists of the elemental symbol of the last noble gas prior to that atom, followed by the configuration of the remaining electrons. So for sodium we make the substitution of (Ne) for the 1s22s22p6 part of the configuration. Sodium's noble gas configuration becomes (Ne) 3s1.

The purpose of this process is to reduce the risk of having outliers of false results.

It is important to bear in mind that a good scientific experiment usually tests one independent variable at a time, and that is why it is important to keep all other potential variables constant and to use a control group.

Although, the experiment you are referring to in your question is missing the general principle when conducting an experiment is the running of multiple tests before coming up with an actual test result.

Therefore, when completing a science experiment it is important to run multiple tests like heating the substance several times until a constant mass value is obtained,  in other to ascertain the results. the reason why such process is undertaken is to reduce the risk of having outliers of false results.  

A scientific experiment involves several procedures and this depends on the type and purpose of the experiment.

for example ;

An experiment with the purpose of determining how the mass of an object reacts to heat will require the mass of the object to be recorded  after heating the object/substance several times.

Hence we can conclude that the purpose of the process is to reduce the risk of having outliers of false results.

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A titration is defined as 'the process of determining the quantity of a substance A by adding measured increments of substance B, the titrant, with which it reacts until exact chemical equivalence is achieved (the equivalence point)'.

The Molarity of the HCl Solution requires the addition of 24.6 mL of titrant is 0.0836 M (to 3 significant figures)

A reagent solution of precisely known concentration that is added in titration

Given reaction HCl + NaOH ===> NaCl + [tex]H_2O[/tex]  neutralization reaction

Note that the mole ratio is 1:1 meaning that 1 mole HCl reacts with 1 mole NaOH to produce 1 mole NaCl and 1 mole [tex]H_2O[/tex]

Find moles of NaOH used:

18.45 ml x 1 L/1000 ml x 0.085 mol/L = 0.002091 moles NaOH used

This meant that there must be 0.002091 moles of HCl present in the 25.0 mls.

We want to find the molarity (M) which is moles HCl/liter of solution.  We know the moles, and we also know the liters of solution (25.0 mls x 1 L / 1000 mls = 0.025 liters)

M = 0.002091 moles HCl / 0.025 liters = 0.08364 M = 0.0836 M (to 3 significant figures)

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The complete equation will look thus: [tex]2HNO_3(aq) + Ba(OH)_2(aq) --- > Ba(NO_3)_2 + 2H_2O[/tex]

In order for equations to be balanced, the component atoms in the reactants and products must be the same in terms of number.

Thus, in the given equation, the number of H, N, O, and Ba atoms in the reactants and the products must be equal.

Therefore, the overall equation becomes:

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Answer:2HNO3 + Ba(OH)2 → Ba(NO3)2 + 2H2O

Explanation:

HNO3 + Ba(OH)2 = Ba(NO3)2 + H2O

This is what each element is....

H= 1+2=3                 H=2

N=1                          N=2

O=2+2=4                O=4+1=5

Ba=1                        Ba=1

Now to balance each side.....

H=2+2=4               H=2++2=4

N=2                       N=2

O=4+2=6              O=4+2=6

Ba=1                      Ba=1

The balanced equation is now

2HNO3 + Ba(OH)2 → Ba(NO3)2 + 2H2O

Answer :]

This is an oxidation-reduction (redox) reaction:

S0 + 2 e- → S-II (reduction)

2 K0 - 2 e- → 2 KI (oxidation)

S is an oxidizing agent, K is a reducing agent.

Answer:

K

Explanation:

Here, in this reaction 2 moles of potassium react with 1 mole of sulfur to form 1 mole of potassium sulfide.

Let's compare the electronic configurations of both elements :

⇒ K = {2, 8, 8, 1}

⇒ K can attain noble gas configuration by losing one electron

⇒ K exists as : K⁺

⇒ S = {2, 8, 6}

⇒ S can attain noble gas configuration by the addition of 2 electrons

⇒ S exists as S²⁻

Now, we know that will lose protons when oxidized. Hence, here the substance which is oxidized is K

Answer: 9.27 g/mL

Explanation:

[tex]d=\frac{m}{v}=\frac{18.53}{2.0}=\boxed{9.27 \text{ g/mL}}[/tex]

The standard enthalpy of formation (Δ[tex]H_f[/tex]) is a measure of the energy released or consumed when one mole of a substance is created under standard conditions from its pure elements.

Standard enthalpies (Δ[tex]H_f[/tex]) of formation for given reaction is 978.3 kJ

The standard enthalpy of formation is defined as the enthalpy change when one mole of a substance in the standard state (1 atm of pressure and 298.15 K) is formed from its pure elements under the same conditions.

Given reaction ;

[tex]N_2O_4(g) + 4H_2 (g) - > N_2(g) + 4H_2O(g)[/tex]

To Find : Δ[tex]H_f[/tex]

Δ[tex]H_f[/tex] = ∑np Δ[tex]H_f[/tex] (products) – ∑np Δ[tex]H_f[/tex] (reactants)

Δ[tex]H_f[/tex] = [1(Δ[tex]H_f[/tex] [tex]N_2[/tex]) + 4(Δ[tex]H_f[/tex] [tex]H_2O[/tex])] – [1(Δ[tex]H_f[/tex] [tex]N_2O_4[/tex]) + 4(Δ[tex]H_f[/tex] [tex]H_2[/tex])]

Δ[tex]H_f[/tex] = [1(0) + 4(-241.8)] – [1(+9.16) + 4(0)]

Δ[tex]H_f[/tex]  = [4(-241.8)] – [1(+9.16)] = 978.3 kJ

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In order to prepare a 50-fold diluted enzyme, 0.1 mL of the stock solution of the enzyme is taken and made up to 5.0 mL with 0.001M HCl.

Dilution is a process whereby a solution of lower concentration is prepared from one of a higher concentration.

Dilution is done by using the dilution formula below:

C1; Initial concentration of enzyme = 1 mg/mL

C2; Final concentration of enzyme = 1/50 mg/ml = 0.02 mg/ml

V1; Initial volume of enzyme = y

V2; Final volume = 5.0 ml

V1 = C2V2/C1

V1 =  0.02 * 5/1 = 0.1 mL

Therefore, in order to prepare a 50-fold diluted enzyme, 0.1 mL of the stock solution of the enzyme is taken and made up to 5.0 mL with 0.001M HCl.

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Answer:

0.3371 moles

Explanation:

gold is 196.967 grams per mole

66.4 grams divided by 196.967 grams per mole =

0.3371 moles

The temperature is the same, so the amount of kinetic energy will also be the same.

Answer:

df  dffdffdfd  dffd  ff d

Explanation:

df fd df f df df dfdf  f fdf  df df df fd

Answer: is is true

Explanation:

Answer:

6.022×1023

Here, it has been asked how many eggs are in one mole of eggs. The eggs represent the unit which can be atom, ion or molecule. So by the definition of mole, 6.022×1023number of eggs are present in one mole of eggs.

In a boys hostel, 1206 eggs would represent 1206 moles of eggs, assuming an average molar mass of 50 grams/mol.

To determine the number of moles of eggs,  first know the molar mass of eggs or the average molar mass of the components in eggs.

Since the composition of eggs can vary, assume an average molar mass based on the most abundant components.

The molar mass of an egg can be estimated to be around 50 grams/mol. This estimate takes into account the approximate composition of eggs, which consists mainly of water, protein, fat, and other components.

Next, convert the mass of eggs to moles.  1 mole of a substance contains Avogadro's number of molecules or entities, which is approximately [tex]6.022 *10^23.[/tex]

Let's calculate the number of moles of eggs:

Mass of eggs = 1206 eggs * 50 grams/egg

= 60300 grams

Moles of eggs = Mass of eggs / molar mass of eggs

= 60300 grams / 50 grams/mol

= 1206 moles

Therefore, 1206 eggs would represent approximately 1206 moles of eggs, assuming an average molar mass of 50 grams/mol.

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When there are two bond pairs and one lone pair, the molecule will have a bent molecular shape.

The shape of a molecule depends on the orientation and number of electron pairs on the valence shell of the central atom in the molecule. This is based on the postulates of the valence shell electron pair repulsion theory.

When there are two bond pairs and one lone pair, the molecule will have a bent molecular shape.

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Answer:

Solution — Molar mass (Molecular mass in gram) of CaCO3 = 40+12+3×16 = 100 g No. of moles of CaCO3 = No. of molecules/Avogadro constant = 6.022 × 1023/ 6.022 × 1023 = 1 mole Mass of CaCO3 = No. of moles × molar mass = 1 × 100 g = 100 g.

Explanation:

The mass of carbon monoxide, CO that must be placed in the 40 L tank is 58.52 g

n = PV / RT

n = (1.27 × 40) / (0.0821 × 296)

n = 2.09 moles

Mass = mole × molar mass

Mass of CO = 2.09 × 28

Mass of CO = 58.52 g

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Answer:

Less expensive than natural fibers

Strong and long-lasting

Easily available

Easy to maintain

Dry up quickly

Answer:

The signs of chemical change include changes in color, temperature, the production of light, changes in odor, and the formation of gases.