Q: Which equation correctly expresses the molarity ($$M) of a $$solution?

$$M = \frac{\text{moles of solute}}{\text{volume of solution in liters}}$$

Q: Which of the following is a correct net ionic equation for the reaction between aqueous solutions of AgNO$$_3$$ and NaCl?

$$\text{Ag}^+ (aq) + \text{Cl}^- (aq) \rightarrow \text{AgCl} (s)$$

Q: Which of the following acids is considered a strong acid?

Hydrochloric acid ($$\text{HCl})$$

Q: Which of the following is a correct example of a redox reaction?

$$\text{Zn} (s) + \text{Cu}^{2+} (aq) \rightarrow \text{Zn}^{2+} (aq) + \text{Cu} (s)$$

Q: Which of the following is the correct formula for calculating the enthalpy change ($$\Delta H) of a $$reaction using standard enthalpies of formation?

$$\Delta H = \sum \Delta H_f$$^{\circ}$$ (\text{products}) - \sum \Delta H_f$$^{\circ}$$ (\text{reactants})$$

Question 1

Which of the following best describes a strong electrolyte in aqueous solution?

Accepted Answer

A compound that completely dissociates into ions, resulting in high conductivity.

Question 2

Which equation correctly expresses the molarity ($$M) of a $$solution?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{volume of solution in liters}}$$

Question 3

A student needs to prepare 250 mL of a 0.50 M NaCl solution. How many grams of NaCl are required? ($$	ext{Molar mass of NaCl} = 58.44\ 	ext{g/mol})$$

Accepted Answer

$$7.31\ 	ext{g}$$

Question 4

Which of the following is a correct net ionic equation for the reaction between aqueous solutions of AgNO$$_3$$ and NaCl?

Accepted Answer

$$	ext{Ag}^+ (aq) + 	ext{Cl}^- (aq) ightarrow 	ext{AgCl} (s)$$

Question 5

Which of the following acids is considered a strong acid?

Accepted Answer

Hydrochloric acid ($$	ext{HCl})$$

Question 6

Which of the following is a correct example of a redox reaction?

Accepted Answer

$$	ext{Zn} (s) + 	ext{Cu}^{2+} (aq) ightarrow 	ext{Zn}^{2+} (aq) + 	ext{Cu} (s)$$

Question 7

Which statement best describes the role of oxidizing agents in redox reactions?

Accepted Answer

They gain electrons and are reduced.

Question 8

Which of the following is the correct formula for calculating the enthalpy change ($$\Delta H) of a $$reaction using standard enthalpies of formation?

Accepted Answer

$$\Delta H = \sum \Delta H_f$$^{\circ}$$ (	ext{products}) - \sum \Delta H_f$$^{\circ}$$ (	ext{reactants})$$

Question 9

A reaction has $$\Delta H = -125\ 	ext{kJ}$$ and $$\Delta S = +85\ 	ext{J/K}. At $$what temperature (in K) does the reaction become non-spontaneous? ($$\Delta G = \Delta H - T\Delta S)$$

Accepted Answer

$$T \u003e 1470\ 	ext{K}$$

Question 10

Which statement correctly describes Hess's Law?

Accepted Answer

The enthalpy change of a reaction is independent of the pathway and depends only on the initial and final states.

Question 11

Which of the following best describes the first law of thermodynamics?

Accepted Answer

Energy cannot be created or destroyed, only transformed.

Question 12

Which formula correctly relates the energy of a photon ($$E) to $$its frequency ($$
u$$)?

Accepted Answer

$$E = h
u$$

Question 13

Which equation represents Planck's formula for the energy of a photon?

Accepted Answer

$$E = h
u$$

Question 14

Which of the following statements about the quantization of energy in atoms is correct?

Accepted Answer

Atoms can only absorb or emit energy in discrete amounts called quanta.

Question 15

Which of the following best explains why sodium chloride (NaCl) is soluble in water?

Accepted Answer

The polar water molecules stabilize the Na$$^+$$ and Cl$$^-$$ ions through ion-dipole interactions.

Question 16

Which of the following is a precipitation reaction?

Accepted Answer

$$	ext{BaCl}_2 (aq) + 	ext{K}_2	ext{SO}_4 (aq) ightarrow 	ext{BaSO}_4 (s) + 2	ext{KCl} (aq)$$

Question 17

Which of the following is the correct relationship between wavelength ($$\lambda$$), frequency ($$
u$$), and the speed of light ($$c$$)?

Accepted Answer

$$c = \lambda 
u$$

Question 18

Which of the following is a correct statement about weak acids?

Accepted Answer

They partially dissociate in water, resulting in a mixture of ions and undissociated acid.

Question 19

A solution is prepared by dissolving 0.10 mol of acetic acid ($$	ext{CH}_3	ext{COOH}) in $$enough water to make 1.0 L of solution. If acetic acid is a weak acid and only 1.3% dissociates, what is the concentration of $$	ext{H}^+$$ ions in the solution?

Accepted Answer

$$1.3 	imes 10$$^{-3}$$\ 	ext{mol/L}$$

General Chemistry Exam 2 Study Guide: Reactions in Aqueous Solution, Thermochemistry, and Electronic Structure of Atoms

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