Question

Question 1
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 weight.

Answer 1

Total mass of compound = 0.24 g (given)
Mass of boron = 0.096 g (given)
Mass of oxygen = 0.144 g (given)
Percent composition of compond: $\frac{Givenmassofelement}{Totalmassofcompound}\times 100$

Thus, percentage of boron by weight in the compound $=\frac{0.096}{0.24}\times 100\%$
$=40\%$
And, percentage of oxygen by weight in the compound
$=\frac{0.144}{0.24}\times 100\%=60\%$