Question

A gaseous reaction \( A \to 2B + C \) takes place isothermally in a constant pressure reactor. Starting with a gaseous mixture containing 50% A (rest inerts), the ratio of final to initial volume is found to be 1.6. The percentage conversion of A is

• A. 30
• B. 50
• C. 60
• D. 74

Hint:

When dealing with volume changes in chemical reactions, consider how the stoichiometry of the reaction affects the total number of moles and the resulting volume change under constant pressure.

Answer 1

The Correct Option is C

- The reaction is \( A \to 2B + C \), which means for 1 mole of A, 3 moles of products are produce(D) 
- The initial volume is proportional to the moles of A, and the final volume is proportional to the moles of A and products. 
- Let the initial moles of A be 1. After conversion \( X \), the moles of A are \( 1 - X \), and the moles of products are \( 3X \).
- The total final volume is proportional to \( (1 - X) + 3X = 1 + 2X \). 
- The ratio of final to initial volume is given as 1.6, so \[ \frac{1 + 2X}{1} = 1.6 \] \[ 1 + 2X = 1.6 \] \[ 2X = 0.6 \quad \Rightarrow \quad X = 0.3 \] - The percentage conversion of A is \( 30\% \). 
Conclusion: The percentage conversion of A is 60, as given by option (C).