Question

The percentage composition of carbon in methane is}

• A. 20 %
• B. 25 %
• C. 75 %
• D. 80 %
• E. 33.3 %

Hint:

To find percentage composition: \[ \text{Percentage}=\frac{\text{mass of required element}}{\text{molecular mass of compound}}\times 100 \] Always calculate the molecular mass first.

Answer 1

The Correct Option is C

Methane has the molecular formula: \[ \text{CH}_4 \] The atomic mass of carbon is: \[ 12 \] The atomic mass of hydrogen is: \[ 1 \] Since methane contains four hydrogen atoms, the total mass of hydrogen is: \[ 4 \times 1 = 4 \] So the molecular mass of methane is: \[ 12 + 4 = 16 \] Now the mass of carbon present in one mole of methane is: \[ 12 \] Therefore, percentage of carbon in methane is: \[ \frac{12}{16} \times 100 \] \[ = 75% \]
Hence, the percentage composition of carbon in methane is: \[ \boxed{75%} \]