Calculate the molecular mass of the following:
a. `H_(2)O`
b. `CO_(2)`
c. `CH_(4)`

Explanation

Molecular mass of `Na_(2)SO_(4)= 2 xx` Atomic mass of `Na +` Atomic mass of `S + 4 xx` Atomic mass of O
`= 2 xx 23 + 32 + 4 xx 16 = 46 + 32 + 64 = 142` u
The percentage of different present can be calculated as :
Percentage of sodium `(Na)=("Mass of Na")/("Molecular mass of "Na_(2)SO_(4))xx100=(46)/(142)xx100=32.39%`
Percentage of sulphur `(S)=("Mass of S")/("Molecular mass of "Na_(2)SO_(4))xx100=(32)/(142)xx100=22.54%`
Percentage of oxygen `(O)=("Mass of O")/("Molecular mass of "Na_(2)SO_(4))xx100=(64)/(142)xx100=45.07%`.