Soln:

a) Molar mass is the mass of one mole of a compound given in a gram.

b)

i. HCl = , H=1, Cl =35.5
HCl = 1 + 35.5
= 36.5

The molar mass of HCl is 36.5 g/mole

ii. NaOH; Na = 23, 0 = 16, H = 1
NaOH = 23 + 16 + 1
= 40

The molar mass of NaOH is 40 g/mole

iii) Sulphuric acid
H₂SO₄ ; H = 1, 0 = 16, S = 32

H₂SO₄ = 2(1) + 32 + (16 × 4)
= 2 + 32 + 64
= 98

The molar mass of sulphuric acid is 98 g/mole

iv) Carbon dioxide ( CO₂)

CO₂ =, C = 12, 0 = 16
CO₂ = 12 + 2 (16)
= 12 + 32
= 44

The molar mass of carbon dioxide is 44 g/mole

v) Sulphur trioxide (SO₃)

SO₃ =, S = 32, 0 = 16
SO₃ = 32 + (16 × 3)
= 32 + 48
= 80

The molar mass of Sulphur trioxide (SO3) is 80 g/mole