Question 1

Which of the following best explains why water has a higher boiling point than methane, despite their similar molar masses?

Accepted Answer

Water molecules form hydrogen bonds, which are stronger than the London dispersion forces present in methane.

Question 2

A student is asked to determine the molar mass of an unknown solute by measuring the freezing point depression of a solution. Which equation should the student use to relate the freezing point depression to the molar mass?

Accepted Answer

$\Delta T_f = K_f \cdot m \cdot i$

Question 3

During a laboratory experiment, a student mixes aqueous solutions of silver nitrate and sodium chloride, resulting in the formation of a white precipitate. Which type of chemical reaction is this, and what is the net ionic equation?

Accepted Answer

It is a precipitation reaction; the net ionic equation is $\mathrm{Ag^+ (aq) + Cl^- (aq) \rightarrow AgCl (s)}$.

Question 4

Which of the following statements about chemical kinetics is correct?

Accepted Answer

The rate of a reaction generally increases with increasing temperature because more molecules have sufficient energy to overcome the activation energy barrier.

Question 5

A reaction is found to be first order in A and second order in B. What is the correct rate law for this reaction?

Accepted Answer

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

Question 6

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

Accepted Answer

A catalyst provides an alternative reaction pathway with a lower activation energy.

Question 7

In a closed system at equilibrium, which of the following statements is true?

Accepted Answer

The concentrations of reactants and products remain constant over time.

Question 8

A solution is prepared by dissolving 0.10 mol of acetic acid ($\mathrm{CH_3COOH}$) in enough water to make 1.0 L of solution. The acid dissociation constant ($K_a$) for acetic acid is $1.8 	imes 10^{-5}$. What is the approximate pH of the solution?

Accepted Answer

2.9

Question 9

Which of the following best explains why sodium chloride ($\mathrm{NaCl}$) dissolves readily in water?

Accepted Answer

The ion-dipole interactions between $\mathrm{Na^+}$ and $\mathrm{Cl^-}$ ions and the polar water molecules are strong enough to overcome the lattice energy of $\mathrm{NaCl}$.

Question 10

Which of the following is the correct expression for the equilibrium constant ($K_{sp}$) for the dissolution of silver chloride ($\mathrm{AgCl}$) in water?

Accepted Answer

$K_{sp} = [\mathrm{Ag^+}][\mathrm{Cl^-}]$

Question 11

A voltaic (galvanic) cell is constructed using a zinc electrode in a $1.0\ \mathrm{M}\ \mathrm{ZnSO_4}$ solution and a copper electrode in a $1.0\ \mathrm{M}\ \mathrm{CuSO_4}$ solution. Which half-reaction occurs at the anode?

Accepted Answer

$\mathrm{Zn (s) \rightarrow Zn^{2+} (aq) + 2e^-}$

Question 12

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

Accepted Answer

The entropy of the universe increases for any spontaneous process.

Question 13

A reaction has $\Delta H = -100\ \mathrm{kJ}$ and $\Delta S = -200\ \mathrm{J/K}$. At what temperature (in K) does the reaction become non-spontaneous?

Accepted Answer

500

Question 14

Which of the following best describes the function of a salt bridge in a galvanic cell?

Accepted Answer

It allows the flow of ions to maintain electrical neutrality in the half-cells.

Question 15

Which of the following laboratory safety procedures is required at all times in the CHE 202 laboratory?

Accepted Answer

Wearing approved eye protection (splash goggles).

Question 16

A student is performing an acid-base titration to determine the concentration of an unknown acid. Which indicator should be chosen?

Accepted Answer

An indicator whose pKa is close to the pH at the equivalence point.

Question 17

Which of the following is the correct relationship 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 18

Which of the following best describes a redox reaction?

Accepted Answer

A reaction in which electrons are transferred from one species to another.

Question 19

A student is asked to predict whether a precipitate will form when 50.0 mL of 0.10 M $\mathrm{Ba(NO_3)_2}$ is mixed with 50.0 mL of 0.10 M $\mathrm{Na_2SO_4}$. The $K_{sp}$ for $\mathrm{BaSO_4}$ is $1.1 	imes 10^{-10}$. What is the correct approach?

Accepted Answer

Calculate the ion product $Q = [\mathrm{Ba^{2+}}][\mathrm{SO_4^{2-}}]$ and compare it to $K_{sp}$.

Question 20

Which of the following best explains why the rate of a reaction increases when the concentration of reactants is increased?

Accepted Answer

There are more frequent collisions between reactant molecules.

CHE 202: General Chemistry and Qualitative Analysis – Course Syllabus and Content Overview

Study Guide - Practice Questions

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