Question

calculate the mass ( in gm ) of one molecule of following compounds. a) CO2 ; b) hcl,, c) H2 so4 ; d) n2 h4​

Answer 1

Answer:

The total sum of the masses of the atoms or elements present in the molecule is termed as molecular mass.

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

= 2 x 1

Molecular mass of H2 = 2 u

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

= 2 x 16

Molecular mass of O2= 32 u

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

= 2 x 35.5

Molecular mass of Cl2 = 71 u

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

= 12 + 2 x 16

Molecular mass of CO2 = 44 u

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

= 12 + 4 x 1

Molecular mass of CH4 = 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

Molecular mass of C2H6 = 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

Molecular mass of C2H4 = 28 u

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

= 14 + 3 x 1

Molecular mass of NH3 = 17 u

ix) Molecular mass of CH3OH= Atomic mass of C + 4 x Atomic mass of H + 1 x Atomic mass of

= 12 + 4 x 1 + 16

Molecular mass of CH3OH = 32 u