Starter Exercise: Calculating the molecular mass

Calculate the molecular mass for each of the following:

·         Ethane

C₂H₆

C=12

H=1

C × 2 = 24

H × 6 = 6

24+6 = 30

·         Benzene

C₆H₆

C=12

H=1

C × 6 = 72

H × 6 = 6

72+6 = 78

·         Cobalt (II)

CoCl₂

Co = 59

Cl = 35.5

Cl × 2 = 71

59+71 = 130

·         Potassium Permanganate

KMnO₄

K = 39

Mn = 55

O = 16

O × 4 = 64

39+55+64 = 158

·         Ammonium Sulphate

(NH₄)₂SO₄

N = 15

H = 1

S = 32

O = 16

N × 2 = 30

H × 2 × 4 = 8

O × 4 = 64

30+8+32+64=134