Q: Given the reaction $$2 CH_4$ (g) + 2 H_2O (g) \rightarrow C_2H_4 (g) + 4 H_2$ (g)$$ and the following thermodynamic data: $$\Delta G^\circ(CH_4$) = -50.8 kJ/$$mol, $$\Delta G^\circ(H_2O) = -228.6 kJ/$$mol, $$\Delta G^\circ(C_2H_4) = 68.1 kJ/$$mol, $$\Delta G^\circ(H_2$) = 0 kJ/$$mol. What is the equilibrium constant $$K_{eq}$$ for this reaction at 25°C?

$$K_{eq} = 4.6 \times 10$$^{-7}$$

Q: Which of the following is the correct formula for calculating the percent hydrolysis of a weak base?

$$\%\text{ hydrolysis} = \frac{\text{amount hydrolyzed}}{\text{initial amount}} \times 100$$

Question 1

Which of the following statements best describes the difference between a state function and an extensive property?

Accepted Answer

A state function is independent of the path taken, while an extensive property depends on the amount of substance present.

Question 2

A buffer is made by dissolving 1.12 g of sodium propionate (C3H5COONa) in 0.100 L solution that contains 0.090 mol of propionic acid (C3H6O2). For propionic acid, $$K_a = 1.3 	imes 10$$^{-5}$$. What is the pH of the buffer? (Assume no volume change.)

Accepted Answer

$$pH = 5.03$$

Question 3

Which of the following is the correct formula for the hypobromite ion?

Accepted Answer

$$BrO^-$$

Question 4

Given the reaction $$2 CH_4$ (g) + 2 H_2O (g) \rightarrow C_2H_4 (g) + 4 H_2$ (g)$$ and the following thermodynamic data: $$\Delta G^\circ(CH_4$) = -50.8 kJ/$$mol, $$\Delta G^\circ(H_2O) = -228.6 kJ/$$mol, $$\Delta G^\circ(C_2H_4) = 68.1 kJ/$$mol, $$\Delta G^\circ(H_2$) = 0 kJ/$$mol. What is the equilibrium constant $$K_{eq}$$ for this reaction at 25°C?

Accepted Answer

$$K_{eq} = 4.6 	imes 10$$^{-7}$$

Question 5

Which of the following best describes a strong electrolyte?

Accepted Answer

A compound that completely ionizes in water, such as NaCl.

Question 6

Calculate the pH of a 0.0020 M NaOH solution.

Accepted Answer

$$pH = 11.30$$

Question 7

Which of the following equations correctly relates the Gibbs free energy change to the equilibrium constant?

Accepted Answer

$$\Delta G = -RT \ln K_{eq}$$

Question 8

A solution contains 0.0350 M Ca(OH)$$_2. $$What is the pOH of the solution?

Accepted Answer

$$pOH = 1.46$$

Question 9

Which of the following is true about the relationship between $$K_c$$ and $$K_p$$ for a reaction involving gases?

Accepted Answer

$$K_p = K_c(RT$$)^{\Delta n}$$, where $$\Delta n$$ is the change in moles of gas.

Question 10

Which of the following is the correct balanced equation for the reaction of cyclohexane ($$C_6H_{12}) $$with oxygen to produce adipic acid ($$C_6H_{10}O_4$) and water?

Accepted Answer

$$2 C_6H_{12} + 5 O_2$ \rightarrow 2 C_6H_{10}O_4$ + 2 H_2O$$

Question 11

Which of the following ions has 18 electrons and a net charge of +2?

Accepted Answer

$$Ca^{2+}$$

Question 12

A 1.4 × 10$$^{-3}$$ mol of argon is placed in a 250 mL bulb. What is the pressure of the argon gas in the light bulb at 27°C? (Use $$R = 0.0821 L$$·atm·mol$$^{-1}$$·K$$^{-1})$$

Accepted Answer

$$P = 0.13$$ atm

Question 13

Which of the following is an example of a weak electrolyte?

Accepted Answer

CH$$_3$$COOH

Question 14

Which of the following best describes the role of an oxidizing agent in a redox reaction?

Accepted Answer

It gains electrons and is reduced.

Question 15

Calculate the $$\Delta H$$ for the reaction: $$C (s) + H_2O (g) \rightarrow CO (g) + H_2$ (g)$$ given the following thermochemical equations:
$$C (s) + O_2$ (g) \rightarrow CO_2$ (g)$$ $$\Delta H = -393.5 kJ$$
$$2 CO (g) + O_2$ (g) \rightarrow 2 CO_2$ (g)$$ $$\Delta H = -566.0 kJ$$
$$2 H_2$ (g) + O_2$ (g) \rightarrow 2 H_2O (g)$$ $$\Delta H = -483.6 kJ$$

Accepted Answer

$$\Delta H = +131.3 kJ$$

Question 16

Which of the following is the correct expression for the equilibrium constant $$K_c$$ for the reaction $$SOCl_2 (g$$) \rightarrow $$SO_2 (g$$) + $$Cl_2 (g$$)$$?

Accepted Answer

$$K_c = \frac{[SO_2$][Cl_2$]}{[$$SOCl_2$$]}$$

Question 17

Which of the following statements about entropy ($$\Delta S) is $$correct?

Accepted Answer

Entropy is a measure of disorder and tends to increase in spontaneous processes.

Question 18

A solution is prepared by adding 15.0 mL of 0.25 M KOH to 35.0 mL of 0.15 M HBr. What is the final pH of the solution?

Accepted Answer

$$pH = 1.85$$

Question 19

Which of the following is the correct formula for calculating the percent hydrolysis of a weak base?

Accepted Answer

$$\%	ext{ hydrolysis} = \frac{	ext{amount hydrolyzed}}{	ext{initial amount}} 	imes 100$$

General Chemistry 101: Final Exam Study Guide

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