Question

For a reaction A + B $\rightarrow$ products $\Delta\text{H}$ is $-$84.2 kJ and $\Delta\text{S}$ is $-$200 J K$^{-1}$. Calculate the highest value of temperature so that the reaction will proceed in forward direction.

• A. 421 K
• B. 237 K
• C.
• D.

Hint:

For a reaction to be spontaneous, $\Delta G<0$. Use the Gibbs-Helmholtz equation, $\Delta G = \Delta H - T\Delta S$. Convert all energy units to be consistent (e.g., J for both $\Delta H$ and $T\Delta S$). Remember to flip the inequality sign when dividing or multiplying by a negative number. The temperature at which $\Delta G = 0$ is the equilibrium temperature, which serves as a boundary for spontaneity.

Answer 1

The Correct Option is A