Question 1

Which of the following best describes the law of conservation of mass as it applies to chemical equations?

Accepted Answer

The total number of atoms of each element must be the same on both sides of the equation.

Question 2

Balance the following equation for the combustion of methane: $$\mathrm{CH_4$ + O_2$ \rightarrow CO_2$ + H_2O}. $$What are the correct coefficients in order (CH$$_4$$, O$$_2$$, CO$$_2$$, H$$_2O$$)?

Accepted Answer

$$1, 2, 1, 2$$

Question 3

Which of the following compounds is most likely to form a precipitate when mixed with an aqueous solution of sodium sulfate ($$\mathrm{Na_2SO_4}$$)?

Accepted Answer

$$\mathrm{$$BaCl_2$$}$$

Question 4

Which of the following is the correct net ionic equation for the reaction between hydrochloric acid ($$\mathrm{HCl}) $$and sodium hydroxide ($$\mathrm{NaOH}) in $$aqueous solution?

Accepted Answer

$$\mathrm{H^+ (aq) + OH^- (aq) \rightarrow H_2O (l)}$$

Question 5

Which of the following statements about redox reactions is TRUE?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 6

In the reaction $$\mathrm{2Na (s) + Cl_2$ (g) \rightarrow 2NaCl (s)}$$, which element is oxidized and which is reduced?

Accepted Answer

Na is oxidized; Cl is reduced.

Question 7

A student mixes aqueous solutions of silver nitrate ($$\mathrm{$$AgNO_3$$}) $$and sodium chloride ($$\mathrm{NaCl}). $$Which of the following best describes what happens?

Accepted Answer

A white precipitate of $$\mathrm{AgCl}$$ forms.

Question 8

Which of the following is the correct oxidation number for sulfur in $$\mathrm{SO_2$}$$?

Accepted Answer

+4

Question 9

Which of the following best describes the role of oxygen in the rusting of iron?

Accepted Answer

Oxygen acts as the oxidizing agent and is reduced.

Question 10

Which of the following is a correct net ionic equation for the precipitation reaction between aqueous solutions of $$\mathrm{Cd(NO_3$)_2}$$ and $$\mathrm{Na_2S}$$?

Accepted Answer

$$\mathrm{Cd$$^{2+}$$ (aq) + S$$^{2-}$$ (aq) \rightarrow CdS (s)}$$

Question 11

Which of the following is the correct balanced equation for the decomposition of sodium chlorate ($$\mathrm{$$NaClO_3$$}) $$when heated?

Accepted Answer

$$2\mathrm{$$NaClO_3$$ (s) \rightarrow 2NaCl (s) + 3O_2 (g)}$$

Question 12

Which of the following is a correct classification for the reaction: $$\mathrm{H_2SO_4 (aq) + 2NaOH (aq) \rightarrow 2H_2O (l) + Na_2SO_4 (aq)}$$?

Accepted Answer

Acid-base neutralization

Question 13

Which of the following is the correct oxidation number for titanium in $$\mathrm{$$TiCl_4$$}$$?

Accepted Answer

+4

Question 14

Which of the following best describes a reducing agent in a redox reaction?

Accepted Answer

It loses electrons and is oxidized.

Question 15

Which of the following is the correct net ionic equation for the reaction of aluminum metal with hydrochloric acid?

Accepted Answer

$$\mathrm{2Al (s) + 6H^+ (aq) \rightarrow 2Al$$^{3+}$$ (aq) + 3H_2 (g)}$$

Question 16

Which of the following best explains why alkali metals are strong reducing agents?

Accepted Answer

They have low ionization energies and readily lose electrons.

Question 17

Which of the following is the correct net ionic equation for the neutralization of acetic acid ($$\mathrm{CH_3COOH}) $$with potassium hydroxide ($$\mathrm{KOH}$$)?

Accepted Answer

$$\mathrm{CH_3COOH (aq) + OH^- (aq) \rightarrow CH_3COO^- (aq) + H_2O (l)}$$

Question 18

Which of the following is a correct statement about spectator ions?

Accepted Answer

They appear unchanged on both sides of an ionic equation.

Question 19

Which of the following reactions is an example of a redox reaction used in metallurgy?

Accepted Answer

$$\mathrm{Fe_2O_3 (s) + 3C (s) \rightarrow 2Fe (s) + 3CO (g)}$$

Classification and Balancing of Chemical Reactions: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards