Use the data in the table below to answer the questions which follow.

Element ............ Ar
H ......................... 1
C ........................ 12
N ........................ 14
O ........................ 16
Na ...................... 23
Mg ..................... 24
Si ....................... 28
S ........................ 32
Cl .................... 35.5
Fe ...................... 56

Calculate the mass of:

a. 1 mole of:
(i) Chlorine molecules

(ii) Iron

(iii) Oxide.

b. 0.5 mole of:

(i) Magnesium nitrate

(ii) Ammonia.