Question

Calculate the molecular masses
of H, O, CL, CO,, CH, CH
CH, NH, CH,OH.
2. Calculate the formula unit
masses of ZnO, Na 0, K,CO,
given atomic masses of Zn = 65 u,
Na = 23 u K= 39 u. C = 12 u.
and 0 = 16 u.​

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 C + 4 x Atomic mass of H + 1 x Atomic mass of

= 12 + 4 x 1 + 16

= 32 u