Question

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

• A. $40,60$
• B. $60,40$
• C. $50,50$
• D. None of the above

Answer 1

The correct option is A $40,60$

Mass % of boron =$\frac{Massofboron}{Massofcompound}\times 100$

$\frac{0.096}{0.24}\times 100=40$

Mass % of oxygen $=\frac{0.144}{0.24}\times 100=60$