Q: A solution is prepared by dissolving 0.5 mol of NaCl in 1.0 kg of water. What is the boiling point elevation if $K_b$ for water is $0.512\ \text{K} \cdot \text{kg} \cdot \text{mol}^{-1}$? (Assume complete dissociation of NaCl.)

$\Delta T_b = 0.512 \times 1 \times 2 = 1.024\ \text{K}$

Q: A buffer solution is made by mixing equal concentrations of acetic acid ($CH_3COOH$) and sodium acetate ($CH_3COONa$). Which equation can be used to calculate the pH of this buffer?

$\text{pH} = \text{p}K_a + \log \left( \dfrac{[\text{A}^-]}{[\text{HA}]} \right)$

Question 1

A reaction is found to be first order with respect to reactant A and second order with respect to reactant B. Which of the following is the correct rate law for this reaction?

Accepted Answer

$	ext{Rate} = k[A][B]^2$

Question 2

Which of the following statements best describes the effect of a catalyst on a chemical reaction?

Accepted Answer

It lowers the activation energy, increasing the reaction rate without being consumed.

Question 3

A solution is prepared by dissolving 0.5 mol of NaCl in 1.0 kg of water. What is the boiling point elevation if $K_b$ for water is $0.512\ 	ext{K} \cdot 	ext{kg} \cdot 	ext{mol}^{-1}$? (Assume complete dissociation of NaCl.)

Accepted Answer

$\Delta T_b = 0.512 	imes 1 	imes 2 = 1.024\ 	ext{K}$

Question 4

Which of the following best describes the entropy change ($\Delta S$) when ice melts at $0^\circ$C?

Accepted Answer

$\Delta S$ is positive because the system becomes more disordered.

Question 5

Given the reaction $N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)$, which of the following will increase the equilibrium concentration of $NH_3$?

Accepted Answer

Increasing the pressure by decreasing the volume.

Question 6

Which of the following is the correct expression for the equilibrium constant $K_c$ for the reaction $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$?

Accepted Answer

$K_c = \dfrac{[SO_3]^2}{[SO_2]^2[O_2]}$

Question 7

A buffer solution is made by mixing equal concentrations of acetic acid ($CH_3COOH$) and sodium acetate ($CH_3COONa$). Which equation can be used to calculate the pH of this buffer?

Accepted Answer

$	ext{pH} = 	ext{p}K_a + \log \left( \dfrac{[	ext{A}^-]}{[	ext{HA}]} ight)$

Question 8

Which of the following will increase the solubility of $AgCl$ in water?

Accepted Answer

Adding $NH_3$, which forms a complex ion with $Ag^+$.

Question 9

Which of the following is the correct cell notation for a galvanic cell with zinc and copper electrodes?

Accepted Answer

$Zn(s) \mid Zn^{2+}(aq) \parallel Cu^{2+}(aq) \mid Cu(s)$

Question 10

Which of the following is true about the relationship between $K$ and $Q$ for a reaction at equilibrium?

Accepted Answer

$Q = K$ and the reaction is at equilibrium.

Question 11

A student titrates 25.0 mL of 0.100 M $HCl$ with 0.100 M $NaOH$. What is the pH at the equivalence point?

Accepted Answer

7.00

Question 12

Which of the following transition metal ions is most likely to form a high-spin octahedral complex?

Accepted Answer

$Fe^{2+}$ with weak field ligands

Question 13

Which of the following correctly describes the effect of increasing temperature on the rate constant $k$ for a reaction, according to the Arrhenius equation?

Accepted Answer

$k$ increases exponentially with temperature.

Question 14

Which of the following is the correct formula for calculating the osmotic pressure ($\Pi$) of a solution?

Accepted Answer

$\Pi = iMRT$

Question 15

Which of the following statements about buffers is correct?

Accepted Answer

A buffer resists changes in pH when small amounts of acid or base are added.

Question 16

Which of the following is the correct expression for the standard free energy change ($\Delta G^\circ$) in terms of the equilibrium constant $K$?

Accepted Answer

$\Delta G^\circ = -RT \ln K$

Question 17

Which of the following will precipitate $BaSO_4$ from a solution containing $Ba^{2+}$ and $SO_4^{2-}$ ions?

Accepted Answer

If $Q_{sp} > K_{sp}$ for $BaSO_4$

Question 18

Which of the following is the correct definition of the half-life ($t_{1/2}$) for a first-order reaction?

Accepted Answer

$t_{1/2} = \dfrac{0.693}{k}$

Question 19

Which of the following is true about the coordination number in transition metal complexes?

Accepted Answer

It is the number of ligand atoms directly bonded to the central metal ion.

CHE 132 Final Exam Study Guide: Kinetics, Colligative Properties, Entropy, Free Energy, Equilibrium, Acid-Base Chemistry, Electrochemistry, and Transition Metals

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