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

Which of the following is the correct balanced chemical equation for the combustion of methane ($$\mathrm{CH_4$}) in $$oxygen?

Accepted Answer

$$\mathrm{CH_4$} + 2\,\mathrm{O_2$} \rightarrow \mathrm{CO_2$} + 2\,\mathrm{H_2O}$$

Question 3

A student mixes aqueous solutions of $$\mathrm{Na_2SO_4}$$ and $$\mathrm{$$BaCl_2$$}. $$What is the net ionic equation for the reaction that occurs?

Accepted Answer

$$\mathrm{Ba$$^{2+}$$ (aq) + SO_4$^{2-} (aq) \rightarrow $$BaSO_4$$ (s)}$$

Question 4

Which of the following compounds is most likely to be insoluble in water, according to the general solubility guidelines?

Accepted Answer

$$\mathrm{AgCl}$$

Question 5

Which of the following best describes an acid-base neutralization reaction?

Accepted Answer

An acid reacts with a base to produce water and a salt.

Question 6

What are the products of the reaction between hydrochloric acid ($$\mathrm{HCl}) $$and sodium carbonate ($$\mathrm{Na_2CO_3}$$)?

Accepted Answer

$$\mathrm{NaCl}$$, $$\mathrm{H_2O}$$, and $$\mathrm{CO_2$}$$

Question 7

Which of the following statements about redox reactions is correct?

Accepted Answer

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

Question 8

In the reaction $$\mathrm{Cu (s) + 2Ag^+ (aq) \rightarrow Cu$$^{2+}$$ (aq) + 2Ag (s)}$$, which species is oxidized and which is reduced?

Accepted Answer

Cu is oxidized; Ag$$^+ is $$reduced.

Question 9

Assign the oxidation number to titanium in $$\mathrm{$$TiCl_4$$}$$ and name the compound using a Roman numeral.

Accepted Answer

Titanium has an oxidation number of +4; the compound is titanium(IV) chloride.

Question 10

Which of the following is the correct net ionic equation for the neutralization of hydrochloric acid with sodium hydroxide?

Accepted Answer

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

Question 11

A piece of iron metal reacts with oxygen in moist air to form rust. Which type of reaction is this, and what is the main chemical process involved?

Accepted Answer

Redox reaction; iron is oxidized as it loses electrons to oxygen.

Question 12

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 13

Which of the following is a correct rule for assigning oxidation numbers?

Accepted Answer

The sum of the oxidation numbers in a neutral compound is zero.

Question 14

Which of the following reactions is best classified as a precipitation reaction?

Accepted Answer

$$\mathrm{$$AgNO_3$$ (aq) + NaCl (aq) \rightarrow AgCl (s) + $$NaNO_3$$ (aq)}$$

Question 15

In the reaction $$\mathrm{Fe_2O_3 (s) + 3CO (g) \rightarrow 2Fe (s) + 3CO_2 (g)}$$, which reactant is the reducing agent?

Accepted Answer

CO

Question 16

Which of the following best describes a net ionic equation?

Accepted Answer

An equation that includes only the ions and molecules directly involved in the chemical change.

Question 17

A solution of $$\mathrm{Pb(NO_3$)_2} is $$mixed with a solution of $$\mathrm{KI}. $$What is the balanced net ionic equation for the reaction?

Accepted Answer

$$\mathrm{Pb$$^{2+}$$ (aq) + 2I^- (aq) \rightarrow $$PbI_2$$ (s)}$$

Question 18

Which of the following real-world processes is an example of a redox reaction?

Accepted Answer

Bleaching hair with hydrogen peroxide

Question 19

Which of the following statements about oxidation and reduction is FALSE?

Accepted Answer

The oxidizing agent is the substance that is oxidized.

Classification and Balancing of Chemical Reactions: Study Notes

Study Guide - Practice Questions