Question

The values of $\Delta H$ and $\Delta S$ for the reaction, $C$ (graphite) $+ CO _{2}( g ) \rightarrow 2 CO ( g )$ are $170\, kJ$ and $170\, JK ^{-1}$ respectively. This reaction will be spontaneous at -

• A. 510 K
• B. 710 K
• C. 910 K
• D. 1110 K

Answer 1

Answer: (D)

For a spontaneous reaction

$\Delta G =- ve$

Or ar eq. $\Delta G =0$

$\Delta H = T \Delta S$

$T =\frac{\Delta H }{\Delta S }$

$=\frac{170 \times 10^{3}}{170}$

$=1000\, K$