A `0.24 g` sample of compound of oxygen and boron was found by analysis to contain `0.096 g` of boron and `0.144 g` of oxygen. Calculate the percentage composition of the compound by mass.

Explanation

(i) Mass of boron in compound `= 0.096 g`
And, Mass of compound `= 0.24 g`
So, `underset(("in compound"))("Percentage of boron") = ("Mass of boron in compound")/("Mass of compound") xx 100`
`= (0.096)/(0.24) xx 100`
`= 40 "……"(1)`
(ii) Mass of oxygen in compound `= 0.144 g`
And, Mass of compound `= 0.24 g`
So, `underset(("in compound"))("Percentage of oxygen") = ("Mass of oxygen in compound")/("Mass of compound") xx 100`
`= (0.144)/(0.24) xx 100`
`= 60 "......."(2)`
Thus, the percentage composition of the compound is : Boron `= 40%` , Oxygen `= 60 %`.