CI1: Nitrogen Chemistry

Question 1

True of False

Nitrogen gas has a triple bond

Answer 1

True

Question 2

What is the shape and bond angle of ammonia?

Answer 2

Trigonal pyramidal and 107 degrees

Due to the repulsive force of the lone pair

Question 3

What is the shape and bond angle of the ammonium ion?

Answer 3

Tetrahedral and 109.5 degrees. Despite the dative covalent bond, there are now 4 areas of electron density.

Question 4

Nitrogen gas is very reactive, true if false?

Answer 4

False, the double bond requires a large amount of energy to break so Nitrogen is very unreactive.

Question 5

Explain ammonia’s solubility in water

Answer 5

Ammonia has a lone pair of electrons which can form hydrogen bonds which makes it very soluble.

Question 6

Why can ammonia act as a ligand in a complex?

Answer 6

The lone pair on the nitrogen can dative covalently bond into the metal centre.

Question 7

Give the ionic equation for the formation of the ammonium ion

Answer 7

NH3 + H+ –> NH4+

Make sure you include the charges
Practice drawing the dot and cross diagram to show the dative covalent bond.

Question 8

Name the three common oxides of nitrogen.

Answer 8

NO nitrogen monoxide
N2O dinitrogen monoxide
NO2 nitrogen dioxide

Question 9

Give the oxidation state of Nitrogen in

NO
NO2
N2O

Answer 9

NO = +2
NO2 = +4
N2O = +1

Question 10

What is the test for the Nitrate (V) ion?

Answer 10

Warm solution with sodium hydroxide in the presence of Devarda’s alloy (or aluminium). Will turn damp red litmus blue.

Question 11

Give the interconversion of ammonium and oxygen to nitrogen dioxide

Answer 11

NH4+ + O2 –> NO2- + 4H+ +2e-

Check the balance of charges with these half equations. Sorry for formatting is difficult it is a negative one charge on the nitrogen dioxide.

Question 12

Give the ionic equation for the release of Nitrogen gas from Nitrate (V)

Answer 12

2NO3- + 12H+ + 10e- –> N2 + 6H2O