Nitrogen family

Question 1

Autoprotolysis in liquid ammonia:

Answer 1

2 NH3(am) ⇌ NH4+(am) + NH2–(am)

Question 2

Reaction of ammonia with d-metal cations:

Answer 2

Cu2+(aq) + 4 NH3(aq) → Cu(NH3)42+(aq)
CuCl2 + 4 NH3 → [Cu(NH3)4]Cl2

Question 3

Decomposition of ammonium salts upon heating:

Answer 3

(NH4)2CO3(s) → 2 NH3(g) + CO2(g) + H2O(g)

Question 4

Oxidation of ammonium cations:

Answer 4

NH4NO3(s) → N2O(g) + 2 H2O(g)
2 NH4NO3(s) → 2 N2(g) + O2(g) + 4 H2O(g)

Question 5

Production of hydrazine:

Answer 5

2 NH3(aq) + ClO–(aq) → N2H4(aq) + Cl–(aq) + H2O(l)
2 NH3(aq) + NaClO ⎯⎯⎯⎯⎯ N2H4(aq) + NaCl +
H2O

Question 6

Reaction of hydrazine with oxygen:

Answer 6

N2H4(aq) + O2(g) → N2(g) + 2 H2O(l)

Question 7

Production of magnesium nitride:

Answer 7

3 Mg(s) + N2(g) →Mg3N2(s)

Question 8

Reaction of nitride with water:

Answer 8

Mg3N2(s) + 6 H2O(l) → 3 Mg(OH)2(s) + 2 NH3(g)

Question 9

Production of sodium azide:

Answer 9

N2O(g) + 2 NaNH2(l) → NaN3(s) + NaOH(s) + NH3(g)

Question 10

Decomposition of sodium azide:

Answer 10

2 NaN3(s) → 2 Na(s) + 3 N2(g)

Question 11

Production of phosphine:

Answer 11

2 P3–(s) + 6 H2O(l) → 2 PH3(g) + 6 OH–(aq)
AlP + 3 H2O → PH3 + Al(OH)3

Question 12

Reactions of phosphorus halogenides with water:

Answer 12

PCl3(l) + 3 H2O(l) → H3PO3(s) + 3 HCl(g)
PCl5(s) + 4 H2O(l) → H3PO4(l) + 5 HCl(g)

Question 13

Production of dinitrogen oxide:

Answer 13

NH4NO3(s) →N2O(g) + 2 H2O(g)

Question 14

Dimerization of nitrogen dioxide:

Answer 14

2 NO2 ⇌ N2O4

Question 15

Production of nitrogen oxide:

Answer 15

4 NH3(g) + 5 O2(g) →4 NO(g) + 6 H2O(g)

Question 16

Production of nitrogen oxide in laboratory:

Answer 16

2 NO2–(aq) + 2 I–(aq) + 4 H+(aq) → 2NO(g) + I2(aq) + 2 H2O(l)
2 KNO2 + 2 KI + 4 HCl → 2NO + I2 + 2 H2O + 4 KCl

Question 17

Oxidation of nitrogen oxide:

Answer 17

2 NO(g) + O2(g) → 2 NO2(g)

Question 18

Reaction of nitrogen dioxide with water:

Answer 18

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

Question 19

Production of nitrous acid:

Answer 19

N2O3(g) + H2O(l) → 2 HNO2(aq)

Question 20

Production of nitrites:

Answer 20

KNO3(s) + Pb(s) → KNO2(s) + PbO(s)

Question 21

Ostwald process:
1. Oxidation of ammonia:

2. Oxidation of nitrogen oxide:
3. Disproportionation of nitrogen dioxide in water:

Answer 21

4N− H3(g) + 5 O2(g) → 4N+ O(g) + 6 H2O(g)
2NO(g) + O2(g) → 2NO2(g)
3N+ O2 (g) + H2O(l) → 2HN+ O3(aq) + N+ O(g)

Question 22

Production of phosphorus(III)oxide:

Answer 22

P4(s, white) + 3 O2(g) → P4O6(s)

Question 23

Production of phosphoric acid:

Answer 23

P4O6(s) + 6 H2O(l) → 4 H3PO3(aq)

Question 24

Production of phosphorous acid:

Answer 24

P4O10(s) + 6 H2O(l) → 4 H3PO4(aq)

Question 25

Production of superphosphate:

Answer 25

Ca3(PO4)2(s) + 2 H2SO4(l) → 2 CaSO4(s) + Ca(H2PO4)2(s)