Question

Calculate the molecular masses of H2 , O2 , Cl2, CO2, CH4, C2H6, C2H4, NH3,

CH3OH.


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Answer 1

Answer:

i) Molecular mass of H2= 2 x Atomic mass of H= 2 x 1

= 2 u

ii) Molecular mass of O2= 2 x Atomic mass of O

= 2 x 16

= 32 u

iii) Molecular mass of Cl2= 2 x Atomic mass of Cl

= 2 x 35.5

= 71 u

iv) Molecular mass of CO2= Atomic mass of C + 2 x Atomic mass of O

= 12 + 2 x 16

= 44 u

v) Molecular mass of CH4= Atomic mass of C + 4 x Atomic mass of H

= 12 + 4 x 1

= 16 u

vi) Molecular mass of C2H6= 2 x Atomic mass of C + 6 x Atomic mass of H

= 2 x 12 + 6 x 1

= 30 u

vii) Molecular mass of C2H4= 2 x Atomic mass of C + 4 x Atomic mass of H

= 2 x 12 + 4 x 1

= 28 u

viii) Molecular mass of NH3= Atomic mass of N + 3 x Atomic mass of H

= 14 + 3 x 1

= 17 u

ix) Molecular mass of CH3OH= Atomic mass of N + 3 x Atomic mass of H

= 12+ 4 x 1+16

= 32 u

Explanation:

Answer 2

Answer:

H2 = 1 * 2 = 2

O2 = 16 * 2 = 32

Cl2 = 35.5 * 2 = 71

CO2 = 12 + 16 * 2 = 44

CH4 = 12 + 1 * 4 = 16

C2H6 = 12 * 2 + 1 * 6 = 30

C2H4 = 12 * 2 + 1 * 4 = 28

NH3 = 14 + 1 * 3 = 17

CH3OH = 12 + 1 * 3 + 16 + 1 = 32