Question 1

Which of the following is the correct net ionic equation for the reaction between sodium carbonate and hydrochloric acid, including the gas formation step?

Accepted Answer

$$2 \mathrm{H}^+ (aq) + \mathrm{CO}_3$$^{2-}$$ (aq) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (l)$$

Question 2

Which of the following statements best describes the role of the oxidizing agent in a redox reaction?

Accepted Answer

It is the substance that is reduced and gains electrons.

Question 3

In the reaction $$2 \mathrm{K} (s) + 2 \mathrm{H}_2\mathrm{O} (l) \rightarrow 2 \mathrm{KOH} (aq) + \mathrm{H}_2 (g)$$, what is the oxidation state change for potassium and hydrogen?

Accepted Answer

Potassium: $$0 \rightarrow +1$$; Hydrogen: $$+1 \rightarrow 0$$

Question 4

Which of the following compounds contains oxygen with an oxidation number of $$-1$$?

Accepted Answer

$$\mathrm{H}_2\mathrm{O}_2$$

Question 5

A student mixes $$\mathrm{Br}_2 (l)$$ with $$\mathrm{NaI} (aq). $$Which of the following best describes what will happen?

Accepted Answer

$$\mathrm{Br}_2$$ will oxidize $$\mathrm{I}^- to$$ $$\mathrm{I}_2$$, and $$\mathrm{Br}_2$$ will be reduced to $$\mathrm{Br}^-.$$

Question 6

Which of the following metals will NOT react with hydrochloric acid to produce hydrogen gas, based on the activity series?

Accepted Answer

Copper

Question 7

What is the oxidation number of chromium in $$\mathrm{Cr}_2\mathrm{O}_7$$^{2-}$$?

Accepted Answer

+6

Question 8

Which of the following reactions is an example of a disproportionation reaction?

Accepted Answer

$$\mathrm{Br}_2 \rightarrow \mathrm{BrO}_3^- + \mathrm{Br}^-$$

Question 9

Balance the following redox reaction and identify the reducing agent: $$\mathrm{Mg} (s) + \mathrm{N}_2 (g) \rightarrow \mathrm{Mg}_3\mathrm{N}_2 (s)$$

Accepted Answer

Balanced: $$3 \mathrm{Mg} (s) + \mathrm{N}_2 (g) \rightarrow \mathrm{Mg}_3\mathrm{N}_2 (s)$$; Reducing agent: $$\mathrm{Mg}$$

Question 10

Which of the following best explains why $$\mathrm{Zn}$$ can displace $$\mathrm{Cu}^{2+}$$ from solution, but $$\mathrm{Cu}$$ cannot displace $$\mathrm{Zn}^{2+}$$?

Accepted Answer

$$\mathrm{Zn} is $$more easily oxidized than $$\mathrm{Cu}$$, so it is higher in the activity series.

Question 11

In the reaction $$2 \mathrm{Na} (s) + \mathrm{Cl}_2 (g) \rightarrow 2 \mathrm{NaCl} (s)$$, which species is the reducing agent and which is the oxidizing agent?

Accepted Answer

Reducing agent: $$\mathrm{Na}$$; Oxidizing agent: $$\mathrm{Cl}_2$$

Question 12

Which of the following is the correct net ionic equation for the reaction of $$\mathrm{SO}_3$$^{2-}$$ with acid to produce a gas?

Accepted Answer

$$\mathrm{SO}_3$$^{2-}$$ (aq) + 2 \mathrm{H}^+ (aq) \rightarrow \mathrm{SO}_2 (g) + \mathrm{H}_2\mathrm{O} (l)$$

Question 13

Which of the following best describes a combustion reaction?

Accepted Answer

A reaction in which a substance reacts with oxygen to produce heat and light.

Question 14

What is the oxidation number of nitrogen in the ammonium ion, $$\mathrm{NH}_4^+$$?

Accepted Answer

-3

Question 15

Which of the following is the correct balanced equation for the combustion of octane ($$\mathrm{C}_8\mathrm{H}_{18}$$)?

Accepted Answer

$$2 \mathrm{C}_8\mathrm{H}_{18} (l) + 25 \mathrm{O}_2 (g) \rightarrow 16 \mathrm{CO}_2 (g) + 18 \mathrm{H}_2\mathrm{O} (g)$$

Question 16

Which of the following statements about oxidation numbers is FALSE?

Accepted Answer

Oxygen always has an oxidation number of $$-2 in $$all compounds.

Question 17

Which of the following is the correct net ionic equation for the reaction of $$\mathrm{S}^{2-}$$ with acid to produce a gas?

Accepted Answer

$$\mathrm{S}^{2-} (aq) + 2 \mathrm{H}^+ (aq) \rightarrow \mathrm{H}_2\mathrm{S} (g)$$

Question 18

Which of the following best describes why $$\mathrm{F}_2$$ can displace $$\mathrm{Cl}^-$$, $$\mathrm{Br}^-$$, and $$\mathrm{I}^-$$ from their salts, but $$\mathrm{Cl}_2$$ cannot displace $$\mathrm{F}^-$$?

Accepted Answer

$$\mathrm{F}_2 is $$the strongest oxidizing agent among the halogens.

chapter 4 lec 2

Guida di studio - Domande di pratica

Study guide - Flashcard