Question 1

Which of the following statements best describes a spontaneous process in thermodynamics?

Accepted Answer

A process that occurs without ongoing outside intervention and results in an increase in the entropy of the universe.

Question 2

The Second Law of Thermodynamics states that for any spontaneous process:

Accepted Answer

The entropy of the universe increases.

Question 3

Which equation correctly relates the change in Gibbs free energy to enthalpy and entropy?

Accepted Answer

$$ \Delta G = \Delta H - T\Delta S $$

Question 4

A reaction has $$ \Delta H = -100 \ \mathrm{kJ} $$ and $$ \Delta S = -200 \ \mathrm{J/K}  at$$ $$ 298 \ \mathrm{K} . Is $$the reaction spontaneous at this temperature?

Accepted Answer

No, because $$ \Delta G  is $$positive.

Question 5

Which of the following best explains why the entropy of a substance increases when it melts?

Accepted Answer

The number of energetically equivalent ways to arrange the particles increases.

Question 6

Which of the following is the correct expression for the standard entropy change of a reaction ($$ \Delta S^\circ_{\mathrm{rxn}} $$)?

Accepted Answer

$$ \Delta S^\circ_{\mathrm{rxn}} = \sum S^\circ_{\mathrm{products}} - \sum S^\circ_{\mathrm{reactants}} $$

Question 7

Which of the following statements about a voltaic (galvanic) cell is correct?

Accepted Answer

Reduction occurs at the cathode and oxidation at the anode.

Question 8

Which equation correctly relates the standard cell potential ($$ E^\circ_{\mathrm{cell}} ) to $$the standard free energy change ($$ \Delta G^\circ $$)?

Accepted Answer

$$ \Delta G^\circ = -nFE^\circ_{\mathrm{cell}} $$

Question 9

A concentration cell is constructed with two copper electrodes. The first half-cell contains $$ 1.0 \ \mathrm{M} $$ $$ \mathrm{Cu}^{2+} $$, and the second contains $$ 0.10 \ \mathrm{M} $$ $$ \mathrm{Cu}^{2+} . At$$ $$ 25^\circ \mathrm{C} $$, what is the direction of electron flow?

Accepted Answer

From the $$ 0.10 \ \mathrm{M} $$ cell to the $$ 1.0 \ \mathrm{M} $$ cell.

Question 10

Which of the following best describes the purpose of a salt bridge in a voltaic cell?

Accepted Answer

To maintain electrical neutrality by allowing the flow of ions.

Question 11

Which of the following nuclear equations correctly represents the beta decay of $$ ^{14}\mathrm{C} $$?

Accepted Answer

$$ ^{14}\mathrm{C} \$$rightarrow ^{14}$$\mathrm{N} $$+ ^{0}$$_{-1}e $$

Question 12

Which of the following statements about alpha, beta, and gamma radiation is correct?

Accepted Answer

Gamma rays have the highest penetrating power and the lowest ionizing power.

Question 13

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

Accepted Answer

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

Question 14

Which of the following best explains why nuclear fusion is not currently used for large-scale electricity production?

Accepted Answer

Fusion reactions require extremely high temperatures and pressures that are difficult to achieve and maintain.

Question 15

Which of the following best describes a network covalent atomic solid?

Accepted Answer

A solid in which atoms are held together in a three-dimensional network by covalent bonds.

Question 16

Which of the following is the correct relationship for the density ($$ d ) of a $$cubic unit cell?

Accepted Answer

$$ d = \frac{nM}{a^3$ N_A} $$

Question 17

Which of the following statements about the packing efficiency of cubic unit cells is correct?

Accepted Answer

Face-centered cubic has the highest packing efficiency among cubic unit cells.

Question 18

Which of the following best describes the difference between a dry-cell battery and a fuel cell?

Accepted Answer

A dry-cell battery contains all reactants within the cell, while a fuel cell requires a continuous supply of reactants from outside.

Question 19

Which of the following equations correctly relates the equilibrium constant ($$ K ) to $$the standard cell potential ($$ E^\circ_{\mathrm{cell}} $$)?

Accepted Answer

$$ E^\circ_{\mathrm{cell}} = \frac{0.0592}{n} \log K $$

General Chemistry Study Guide: Thermodynamics, Electrochemistry, Nuclear Chemistry, and Crystalline Solids

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