Calculate the molecular mass of the following

Calculate the molecular mass of the following.
(i) $H { 2 }O$
(ii) $C{{O}
{2}}$
(iii) $C{{H}_{4}}$

(i) Molecular mass of $H { 2 }O$ = 2 X atomic mass of hydrogen +1 X atomic mass of oxygen
= 2x 1.0079 u+lx 16.00 u= 18.0158 u
(ii) Molecular mass of $C{{O}
{2}}$ = 1X atomic mass of carbon + 2 X atomic mass of oxygen
= lx 12.01 u+2x16.00 u= 44.01 u
(iii) Molecular mass of $C{{H}_{4}}$ = 1 X atomic mass of carbon + 4 x atomic mass of hydrogen = 1x12.01 u + 4 x 1.0079 u = 16.0416