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 is the correct set of coefficients?

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 $$\mathrm{$$AgNO_3$$}$$?

Accepted Answer

$$\mathrm{NaI}$$

Question 4

Which of the following is the correct net ionic equation for the reaction between $$\mathrm{$$AgNO_3$$(aq)}$$ and $$\mathrm{NaCl(aq)}$$?

Accepted Answer

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

Question 5

Which of the following statements about acids and bases is correct?

Accepted Answer

A neutralization reaction between an acid and a base always produces water and a salt.

Question 6

What is the oxidation number of sulfur in $$\mathrm{H_2SO_4}$$?

Accepted Answer

$$+6$$

Question 7

Which of the following reactions is a redox reaction?

Accepted Answer

$$\mathrm{2AgNO_3(aq) + Cu(s) \rightarrow 2Ag(s) + Cu(NO_3$)_2(aq)}$$

Question 8

Which species is the reducing agent in the reaction $$\mathrm{Cu(s) + 2Ag^+(aq) \rightarrow Cu$$^{2+}$$(aq) + 2Ag(s)}$$?

Accepted Answer

$$\mathrm{Cu(s)}$$

Question 9

A student mixes aqueous solutions of $$\mathrm{Pb(NO_3$)_2}$$ and $$\mathrm{KI}. $$What is the balanced molecular equation for the reaction?

Accepted Answer

$$\mathrm{Pb(NO_3$)_2(aq) + 2KI(aq) \rightarrow $$PbI_2$$(s) + 2KNO_3(aq)}$$

Question 10

Which of the following best describes a spectator ion?

Accepted Answer

An ion that does not participate in the chemical change during a reaction.

Question 11

Which of the following is the correct net ionic equation for the neutralization of $$\mathrm{HCl}$$ with $$\mathrm{Ca(OH)_2}$$?

Accepted Answer

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

Question 12

Which of the following is a correct statement about oxidation and reduction?

Accepted Answer

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

Question 13

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

Accepted Answer

They have low ionization energies, making it easy for them to lose electrons.

Question 14

What is the oxidation number of nitrogen in $$\mathrm{NO_3$^-}$$?

Accepted Answer

$$+5$$

Question 15

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

Accepted Answer

$$\mathrm{$$BaCl_2$$(aq) + Na_2SO_4(aq) \rightarrow $$BaSO_4$$(s) + 2NaCl(aq)}$$

Question 16

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

Accepted Answer

$$2NaClO_3 \rightarrow 2NaCl + 3O_2$$

Question 17

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

Accepted Answer

The rusting of iron in moist air.

Question 18

In the reaction $$\mathrm{2Al(s) + 3Cl_2(g) \rightarrow 2AlCl_3(s)}$$, which element is oxidized?

Accepted Answer

Aluminum

Question 19

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

Accepted Answer

It loses electrons and is oxidized.

Classification and Balancing of Chemical Reactions: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards