Question

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

Given: 

- Total mass of the compound = 0.24 g
- Mass of boron = 0.096 g
- Mass of oxygen = 0.144 g

To calculate the percentage composition:

The formula for percentage composition is:

\[ \text{Percentage of element} = \left( \frac{\text{Mass of element}}{\text{Total mass of compound}} \right) \times 100 \]

Calculation:

1. Percentage of boron: \[ \text{Percentage of boron} = \left( \frac{0.096}{0.24} \right) \times 100 = 40\% \]
2. Percentage of oxygen: \[ \text{Percentage of oxygen} = \left( \frac{0.144}{0.24} \right) \times 100 = 60\% \]

Final Answer:

The percentage composition of the compound is:

• Boron (B) 40%