Skip to main content

# 22.E: Chemistry of the Nonmetals (Exercises)

These are homework exercises to accompany the Textmap created for "Chemistry: The Central Science" by Brown et al. Complementary General Chemistry question banks can be found for other Textmaps and can be accessed here. In addition to these publicly available questions, access to private problems bank for use in exams and homework is available to faculty only on an individual basis; please contact Delmar Larsen for an account with access permission.

## 22.3: Group 18: Nobel Gases

### Questions

1. The chemistry of the noble gases is largely dictated by a balance between two competing properties. What are these properties? How do they affect the reactivity of these elements?
2. Of the group 18 elements, only krypton, xenon, and radon form stable compounds with other atoms and then only with very electronegative elements. Why?
3. Give the type of hybrid orbitals used by xenon in each species.
1. XeF2
2. XeF4
3. XeO3
4. XeOF4
5. XeO4
6. XeO64−
1. Which element is the least metallic—B, Ga, Tl, Pb, Ne, or Ge?
2. Of Br, N, Ar, Bi, Se, He, and S, which would you expect to form positive ions most easily? negative ions most easily?
3. Of BCl3, BCl4, CH4, H3N·BF3, PCl3, PCl5, XeO3, H2O, and F, which species do you expect to be
1. electron donors?
2. electron acceptors?
3. neither electron donors nor acceptors?
4. both electron donors and acceptors?
1. Of HCl, HClO4, HBr, H2S, HF, KrF2, and PH3, which is the strongest acid?
2. Of CF4, NH3, NF3, H2O, OF2, SiF4, H2S, XeF4, and SiH4, which is the strongest base?

### Structure and Reactivity

1. Write a balanced chemical equation showing how you would prepare each compound from its elements and other common compounds.
1. XeF2
2. XeF4
3. XeF6
4. XeOF4
5. XeO3
1. Write a balanced chemical equation showing how you would make each compound.
1. XeF2 from Xe gas
2. NaXeF7 from its elements
3. RnO3 from Rn
1. In an effort to synthesize XeF6, a chemist passed fluorine gas through a glass tube containing xenon gas. However, the product was not the one expected. What was the actual product?
2. Write a balanced chemical equation to describe the reaction of each species with water.
1. B2H6
2. F2
3. C4+
1. Using heavy water (D2O) as the source of deuterium, how could you prepare each compound?
1. LiAlD4
2. D2SO4
3. SiD4
4. DF
2. Predict the product(s) of each reaction and write a balanced chemical equation for each reaction.

1. Al2O3(s) in OH(aq)
2. Ar(g) + F2(g)
3. PI3(s) + H2O(l)
4. H3PO3(l) + OH(aq)
5. Bi(s) + excess Br2(l)

### Answers

1. Xe(g) + F2(g) → XeF2(s)
2. Xe(g) + 2F2(g) → XeF4(s)
3. Xe(g) + 3F2(g) → XeF6(s)
4. 2XeF6(s) + SiO2(s) → 2XeOF4(l) + SiF4(l)
5. XeF6(s) + 3H2O(l) → XeO3(s) + 6HF(aq)
1. SiF4; SiO2(s) + 2F2(g) → SiF4(l) + 2O2(g)
1.
1. 2Na(s) + 2D2O(l) → D2(g) + 2NaOD(aq)

2Li(s) + D2(g) → 2LiD(s)

4LiD(s) + AlCl3(soln) → LiAlD4(s) + 3LiCl(soln)

1. D2O(l) + SO3(g) → D2SO4(l)
2. SiCl4(l) + LiAlD4(s) [from part (a)] → SiD4(g) + LiCl(s) + AlCl3(s)
3. CaF2(s) + D2SO4(l) [from part (b)] → 2DF(g) + CaSO4(s)

## 22.4: Group 7A: The Halogens

### Questions

1. The lightest elements of groups 15, 16, and 17 form unusually weak single bonds. Why are their bonds so weak?
2. Fluorine has an anomalously low F–F bond energy. Why? Why does fluorine form compounds only in the −1 oxidation state, whereas the other halogens exist in multiple oxidation states?
3. Compare AlI3, InCl3, GaF3, and LaBr3 with respect to the type of M–X bond formed, melting point, and solubility in nonpolar solvents.
4. What are the formulas of the interhalogen compounds that will most likely contain the following species in the indicated oxidation states: I (+3), Cl (+3), I (−1), Br (+5)?
5. Consider this series of bromides: AlBr3, SiBr4, and PBr5. Does the ionic character of the bond between the Br atoms and the central atom decrease or increase in this series?
6. Chromium forms compounds in the +6, +3, and +2 oxidation states. Which halogen would you use to produce each oxidation state? Justify your selections.
7. Of ClF7, BrF5, IF7, BrF3, ICl3, IF3, and IF5, which one is least likely to exist? Justify your selection.

### Answers

1. Electrostatic repulsions between lone pairs on adjacent atoms decrease bond strength.
1. Ionic character decreases as Δχ decreases from Al to P.
1. ClF7

### Structure and Reactivity

1. SiF4 reacts easily with NaF to form SiF62−. In contrast, CF4 is totally inert and shows no tendency to form CF62− under even extreme conditions. Explain this difference.
2. Predict the products of each reaction and then balance each chemical equation.
1. Xe(g) + excess F2(g) →
2. Se(s) + Cl2(g) →
3. SO2(g) + Br2(g) →
4. NaBH4(s) + BF3(soln) →
1. Write a balanced chemical equation for the reaction of aqueous HF with
1. SiO2.
2. Na2CO3.
3. CaO.
1. Oxyhalides of sulfur, such as the thionyl halides (SOX2, where X is F, Cl, or Br), are well known. Because the thionyl halides react vigorously with trace amounts of water, they are used for dehydrating hydrated metal salts. Write a balanced chemical equation to show the products of reaction of SOCl2 with water.
1. Write a balanced chemical equation describing each reaction.
1. the burning of sulfur in a chlorine atmosphere
2. the dissolution of iodine in a potassium iodide solution
3. the hydrolysis of PCl3
4. the preparation of HF from calcium fluoride and sulfuric acid
5. the thermal decomposition of KClO3
6. the oxidation of sulfide ion by elemental iodine
1. Write the complete Lewis electron structure, the type of hybrid used by the central atom, and the number of lone pair electrons present on the central atom for each compound.
1. CF4
2. PCl3
3. XeF4

### Answers

1. Carbon has no low energy d orbitals that can be used to form a set of d2sp3 hybrid orbitals. It is also so small that it is impossible for six fluorine atoms to fit around it at a distance that would allow for formation of strong C–F bonds.
1.
1. SiO2(s) + 6HF(aq) → SiF62−(aq) + 2H+(aq) + 2H2O(l)
2. Na2CO3(s) + 2HF(aq) → CO2(g) + 2NaF(aq) + H2O(l)
3. CaO(s) + 2HF(aq) → CaF2(s) + H2O(l)
1.
1. S8(s) + 4Cl2(g) → 4S2Cl2(l)
2. I2(s) + KI(aq) → I3(aq) + K+(aq)
3. PCl3(l) + 3H2O(l) → H3PO3(aq) + 3HCl(aq)
4. CaF2(s) + H2SO4(aq) → 2HF(aq) + CaSO4(s)
5. 2KClO3(s) $$\xrightarrow{\Delta}$$ 2KCl(s) + 3O2(g)
6. 8S2−(aq) + 8I2(aq) → S8(s) + 16I(aq)

## 22.7: Nitrogen

### Problems

• Complete and balance the following equations

N2 + ___H2→ ___NH_

H2N2O2 → ?

2NH3 + CO2 → ?

__Mg + N2 → Mg_N_

N2H5 + H2O → ?

• What are the different isotopes of Nitrogen?
• List the oxiadation states of various nitrogen oxides: N2O, NO, N2O3, N2O4, N2O5
• List the different elements that Nitrogen will react with to make it basic or acidic....
• Uses of nitrogen

### Answers

• Complete and balance the following equations

N2 + 3H2→ 2NH3(Haber process)

H2N2O2 → HNO

2NH3 + CO2 → (NH2)2CO + H2O

2Mg + 3N2 → Mg3N2

N2H5 + H2O → N2+ H+ + H2O

• What are the different isotopes of Nitrogen?

Stable forms include nitrogen-14 and nitrogen-15

• List the oxidation states of various nitrogen oxides: +1, +2, +3, +4, +5 respectively
• List the different elements that Nitrogen will react with to make it basic or acidic :Nitride ion is a strong base when reacted with water, Ammonia is generally a  weak acid
• Uses of nitrogen include anesthetic, Refrigerant, metal protector