Question 1

Which of the following statements best explains why nitrogen (N₂) has a much lower boiling point than phosphorus (P₄)?

Accepted Answer

Nitrogen has weaker intermolecular forces due to its small, nonpolar diatomic molecules.

Question 2

Which reaction represents the industrial fixation of nitrogen in the Haber process?

Accepted Answer

$$\mathrm{N_2$(g) + 3H_2(g) \rightarrow 2NH_3(g)}$$

Question 3

Which property increases as you move down Group 5A(15) from nitrogen to bismuth?

Accepted Answer

Metallic character

Question 4

Which of the following oxides of nitrogen is commonly known as laughing gas and is used as a dental anesthetic?

Accepted Answer

$$\mathrm{N_2O} ($$Dinitrogen monoxide)

Question 5

Which of the following best describes the trend in acid strength for oxoacids of the same halogen as the oxidation state increases?

Accepted Answer

Acid strength increases as oxidation state increases.

Question 6

Which of the following reactions is an example of disproportionation involving nitrogen oxides?

Accepted Answer

$$\mathrm{3NO(g) \rightarrow N_2O(g) + NO_2$(g)}$$

Question 7

Which of the following statements about the hydrides of Group 6A(16) elements is correct?

Accepted Answer

Hydride bond angles decrease and bond lengths increase down the group.

Question 8

Which of the following best explains why $$\mathrm{F_2$}$$ has a lower bond energy than $$\mathrm{Cl_2$}$$, despite being a smaller molecule?

Accepted Answer

Lone pair repulsions on the small F atoms weaken the F–F bond.

Question 9

Which of the following is a correct statement about the oxidizing ability of the halogens?

Accepted Answer

$$\mathrm{Cl_2$}$$ can oxidize $$\mathrm{I^-} to$$ $$\mathrm{I_2$}$$, but $$\mathrm{I_2$}$$ cannot oxidize $$\mathrm{Cl^-}.$$

Question 10

Which of the following noble gases is most likely to form compounds, and why?

Accepted Answer

Xenon, because it has a relatively low ionization energy and a large atomic size.

Question 11

Which of the following best describes the trend in the acid-base character of Group 5A(15) oxides as you move down the group?

Accepted Answer

Oxides change from acidic to amphoteric to basic.

Question 12

Which of the following is a correct statement about the solubility and reactivity of nitrate salts?

Accepted Answer

Nitrate ($$\mathrm{NO_3$^-}) $$acts as an oxidizing agent and all nitrate salts are water soluble.

Question 13

Which of the following best explains why $$\mathrm{H_3PO_3}$$ has only two acidic hydrogen atoms?

Accepted Answer

One hydrogen is bonded directly to phosphorus and does not dissociate.

Question 14

Which of the following is a correct statement about the formation of polyphosphates?

Accepted Answer

Polyphosphates contain P–O–P linkages formed by dehydration-condensation reactions.

Question 15

Which of the following best describes the trend in the stability of halides formed by Group 6A(16) elements as the central atom becomes larger?

Accepted Answer

Halides become more stable as the central atom becomes larger.

Question 16

Which of the following reactions is used in the industrial production of nitric acid (Ostwald process)?

Accepted Answer

$$\mathrm{3NO_2(g) + H_2O(l) \rightarrow 2HNO_3(aq) + NO(g)}$$

Question 17

Which of the following best explains why $$\mathrm{SO_2$} is a $$choking gas and a significant air pollutant?

Accepted Answer

$$\mathrm{SO_2$} is $$formed from the combustion of sulfur-containing fuels and is toxic to respiratory systems.

Question 18

Which of the following statements about the noble gases is correct?

Accepted Answer

Noble gases have the highest ionization energies in their periods.

Question 19

Which of the following best describes the structure of the most stable allotrope of sulfur at room temperature?

Accepted Answer

A crown-shaped ring of eight sulfur atoms (cyclo-$$\mathrm{S_8$}).$$

Periodic Patterns in the Main-Group Elements: Groups 5A(15), 6A(16), 7A(17), and 8A(18)

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