Question

Which of the following graphs represents an exothermic reaction?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

According to van't Hoff equation

$logK=\left[-\frac{\Delta H^{\circ }}{2.303R}\right]\times \frac{1}{T}+\frac{\Delta S^{\circ }}{R}$

$Y=Mx+C$

When log K is plotted against $\frac{1}{T}$ , we get straight line having slope equal to $\left[-\frac{\Delta H^{\circ }}{2.303R}\right]$

For exothermic reaction, slope of the line will be positive.