Question 1

Which of the following is a chemical change?

Accepted Answer

A silver surface becoming tarnished after exposure to air for a long period of time

Question 2

Which property of isopropyl alcohol is a chemical property?

Accepted Answer

Flammable

Question 3

Which of the following best describes the change when natural gas burns in a stove?

Accepted Answer

Chemical change because new substances are formed

Question 4

Consider the reaction: $2\ \mathrm{Al}(s) + 3\ \mathrm{Cl}_2(g) \rightarrow 2\ \mathrm{AlCl}_3(s)$. If you start with $2.0\ \mathrm{g}$ Al and $2.4\ \mathrm{g}$ Cl$_2$, what is the theoretical yield of AlCl$_3$ (in grams)? (Molar masses: Al = 27.0 g/mol, Cl$_2$ = 70.9 g/mol, AlCl$_3$ = 133.5 g/mol)

Accepted Answer

2.3 g

Question 5

Which of the following is the correct balanced equation for the combustion of hexane ($\mathrm{C}_6\mathrm{H}_{14}$)?

Accepted Answer

$\mathrm{C}_6\mathrm{H}_{14}(g) + 9\ \mathrm{O}_2(g) \rightarrow 6\ \mathrm{CO}_2(g) + 7\ \mathrm{H}_2\mathrm{O}(g)$

Question 6

A reaction mixture contains $4.2$ mol ZnS and $6.8$ mol O$_2$. According to the reaction $2\ \mathrm{ZnS}(s) + 3\ \mathrm{O}_2(g) \rightarrow 2\ \mathrm{ZnO}(s) + 2\ \mathrm{SO}_2(g)$, how many moles of the excess reactant remain after the reaction goes to completion?

Accepted Answer

2.8 mol O$_2$

Question 7

Which of the following best describes the process when a platinum ring becomes dull because of continued abrasion?

Accepted Answer

Physical change

Question 8

Given the reaction $2\ \mathrm{N}_2\mathrm{H}_4(g) + \mathrm{N}_2\mathrm{O}_4(g) \rightarrow 3\ \mathrm{N}_2(g) + 4\ \mathrm{H}_2\mathrm{O}(g)$, if you start with $2.5$ mol N$_2$H$_4$ and $4.2$ mol N$_2$O$_4$, what is the limiting reactant?

Accepted Answer

N$_2$H$_4$

Question 9

Which of the following is a physical property of ozone (O$_3$) as a pollutant in the lower atmosphere?

Accepted Answer

Colorless

Question 10

For the reaction $\mathrm{FeS}(s) + 2\ \mathrm{HCl}(aq) \rightarrow \mathrm{FeCl}_2(aq) + \mathrm{H}_2\mathrm{S}(g)$, what mass of H$_2$S (in g) is produced when $3.2$ g FeS reacts completely? (Molar masses: FeS = 87.9 g/mol, H$_2$S = 34.1 g/mol)

Accepted Answer

1.24 g

Question 11

Which of the following best describes the change when a bicycle frame rusts on repeated exposure to air and water?

Accepted Answer

Chemical change

Question 12

Which of the following equations is correctly balanced?

Accepted Answer

$2\ \mathrm{Al}(s) + 3\ \mathrm{H}_2\mathrm{SO}_4(aq) \rightarrow \mathrm{Al}_2(\mathrm{SO}_4)_3(aq) + 3\ \mathrm{H}_2(g)$

Question 13

Which of the following is a chemical property of ethyl alcohol?

Accepted Answer

Tendency of ethyl alcohol to burn

Question 14

A student mixes $3.0$ mol C and $6.0$ mol SiO$_2$ for the reaction $\mathrm{SiO}_2(s) + 3\ \mathrm{C}(s) \rightarrow \mathrm{SiC}(s) + 2\ \mathrm{CO}(g)$. How many moles of SiC can be formed?

Accepted Answer

1.0 mol

Question 15

Which of the following best describes the process when sugar burns when heated in a skillet?

Accepted Answer

Chemical change

Question 16

For the reaction $2\ \mathrm{NO}(g) + 5\ \mathrm{H}_2(g) \rightarrow 2\ \mathrm{NH}_3(g) + 2\ \mathrm{H}_2\mathrm{O}(g)$, a mixture contains $5$ mol NO and $10$ mol H$_2$. After the reaction goes to completion, how many moles of NH$_3$ and H$_2$O are formed?

Accepted Answer

4 mol NH$_3$, 4 mol H$_2$O

Question 17

Which of the following is a physical change?

Accepted Answer

Evaporation of water

Question 18

Which of the following best describes the process when a liquid at room temperature evaporates?

Accepted Answer

Physical change

Question 19

Which of the following is the correct balanced equation for the reaction of solid sodium with chlorine gas to form sodium chloride?

Accepted Answer

$2\ \mathrm{Na}(s) + \mathrm{Cl}_2(g) \rightarrow 2\ \mathrm{NaCl}(s)$

Chapter 7: Chemical and Physical Changes – Study Notes and Problem Guide

Study Guide - Practice Questions

Study Guide - Flashcards