Question

Calculate heat of formation of \(\text{SO}_2\) from following equations.
\( \text{S} + \frac{3}{2}\text{O}_2 \longrightarrow \text{SO}_3, \Delta \text{H} = -2\text{x kJ} \)
\( \text{SO}_2 + \frac{1}{2}\text{O}_2 \longrightarrow \text{SO}_3, \Delta \text{H} = -\text{y kJ} \)

• A. \(\text{y} - 2\text{x}\)
• B. \(2\text{x} - \text{y}\)
• C. \(2\text{x} + \text{y}\)
• D. \(\frac{2\text{x}}{\text{y}}\)

Hint:

Hess law: Reverse → sign changes, then add equations.

Answer 1

The Correct Option is B