Question 1

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

Accepted Answer

A catalyst lowers the activation energy $$E_a$$ and increases the rate of reaction without being consumed.

Question 2

A student mixes 0.10 M acetic acid ($$CH_3COOH) $$with 0.10 M sodium acetate ($$CH_3COONa) to $$prepare a buffer. Which equation should be used to calculate the pH of this buffer solution?

Accepted Answer

The Henderson-Hasselbalch equation: $$pH = pK_a + \log \left( \frac{[A^-]}{[HA]} \right)$$

Question 3

Which of the following best explains why increasing temperature generally increases the rate of a chemical reaction?

Accepted Answer

It increases the number of effective collisions between reactant molecules.

Question 4

A solution of $$NH_4Cl is $$added to a saturated solution of $$AgCl. $$What will happen to the solubility of $$AgCl$$?

Accepted Answer

The solubility of $$AgCl$$ will decrease due to the common ion effect.

Question 5

Which of the following is the correct expression for the equilibrium constant $$K_{eq}$$ for the reaction: $$aA + bB \rightleftharpoons cC + dD$$?

Accepted Answer

$$K_{eq} = \frac{[C]^c [D]^d}{[A]^a [B]^b}$$

Question 6

Which of the following processes is spontaneous at standard conditions?

Accepted Answer

A process with $$\Delta G \u003c 0$$

Question 7

Which statement correctly describes a Bronsted-Lowry acid?

Accepted Answer

A Bronsted-Lowry acid is a substance that donates a proton ($$H^+).$$

Question 8

A voltaic cell is constructed using the following half-reactions: $$Zn^{2+} + 2e$$^- \rightarrow Zn$$ and Cu$$^{2+}$$ + 2e^- \rightarrow Cu. $$Which metal acts as the anode?

Accepted Answer

Zinc ($$Zn)$$

Question 9

Which of the following best describes the effect of adding more $$CO_2$$ gas to the equilibrium system: $$CO_2(g) + H_2O(l$$) \rightleftharpoons H_2CO_3(aq)$$?

Accepted Answer

The equilibrium will shift to the right, producing more $$H_2CO_3.$$

Question 10

Which of the following is the correct formula for calculating the standard cell potential $$E^\circ_{cell} of an $$electrochemical cell?

Accepted Answer

$$E^\circ_{cell} = E^\circ_{cathode} - E^\circ_{anode}$$

Question 11

Which of the following is a correct statement about the entropy change $$\Delta S in a $$chemical reaction?

Accepted Answer

An increase in entropy ($$\Delta S \u003e 0) $$generally favors spontaneity.

Question 12

Which of the following is the correct balanced nuclear equation for the alpha decay of $$^{238}U$$?

Accepted Answer

$$^{238}U \$$rightarrow ^{234}$$Th $$+ ^{4}$$He$$

Question 13

Which of the following is the correct expression for the rate law of a reaction that is first order in $$A$$ and second order in $$B$$?

Accepted Answer

$$rate = k[A][B]^2$$

Question 14

Which of the following statements about coordination compounds is correct?

Accepted Answer

The coordination number refers to the number of ligands directly bonded to the central metal ion.

Question 15

Which of the following is the correct formula for the solubility product constant $$K_{sp}$$ for $$CaF_2$$?

Accepted Answer

$$K_{sp} = [Ca$$^{2+}$$][F^-]^2$$

Question 16

A buffer solution is prepared by mixing equal concentrations of a weak acid and its conjugate base. What is the pH of the buffer relative to the $$pK_a of $$the acid?

Accepted Answer

The pH is equal to the $$pK_a.$$

Question 17

Which of the following is a correct statement about the Nernst equation?

Accepted Answer

It relates the cell potential to the concentrations of reactants and products.

Question 18

Which of the following is the correct definition of a Lewis acid?

Accepted Answer

A Lewis acid is a substance that accepts an electron pair.

Question 19

Which of the following best describes the role of entropy ($$\Delta S) $$and enthalpy ($$\Delta H) in $$determining the spontaneity of a process at constant temperature and pressure?

Accepted Answer

A process is spontaneous if $$\Delta G = \Delta H - T\Delta S is $$negative.

General Chemistry II (CHE117) Syllabus and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard