Search any question & find its solution
Question:
Answered & Verified by Expert
The heat of formation of $\mathrm{CO}(\mathrm{g})$ and $\mathrm{CO}_2(\mathrm{~g})$ are $\Delta H=-110$ and $\Delta H=-393 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. What is the heat of reaction $(\Delta H)$ (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) for the following reaction?
$\mathrm{CO}(\mathrm{g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{CO}_2(\mathrm{~g})$
Options:
$\mathrm{CO}(\mathrm{g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{CO}_2(\mathrm{~g})$
Solution:
1576 Upvotes
Verified Answer
The correct answer is:
-283
$\begin{aligned}
& \mathrm{C}+\frac{1}{2} \mathrm{O}_2 \longrightarrow \mathrm{CO}, \Delta H=-110 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots \text { (i) } \\
& \mathrm{C}+\mathrm{O}_2 \longrightarrow \mathrm{CO}_2, \quad \Delta H=-393 \mathrm{~kJ} \mathrm{~mol}^{-1} \\
& \ldots \text { (ii) }
\end{aligned}$
On subtracting Eq. (i) from Eq. (ii), we get
$\begin{aligned}
\mathrm{CO} & +\frac{1}{2} \mathrm{O}_2 \longrightarrow \mathrm{CO}_2 \\
\Delta H & =393-(-110) \\
& =-283 \mathrm{~kJ} \mathrm{~mol}^{-1}
\end{aligned}$
& \mathrm{C}+\frac{1}{2} \mathrm{O}_2 \longrightarrow \mathrm{CO}, \Delta H=-110 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots \text { (i) } \\
& \mathrm{C}+\mathrm{O}_2 \longrightarrow \mathrm{CO}_2, \quad \Delta H=-393 \mathrm{~kJ} \mathrm{~mol}^{-1} \\
& \ldots \text { (ii) }
\end{aligned}$
On subtracting Eq. (i) from Eq. (ii), we get
$\begin{aligned}
\mathrm{CO} & +\frac{1}{2} \mathrm{O}_2 \longrightarrow \mathrm{CO}_2 \\
\Delta H & =393-(-110) \\
& =-283 \mathrm{~kJ} \mathrm{~mol}^{-1}
\end{aligned}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.