The effect of temperature on spontaneity of reactions are represented as :

	$\Delta$H	$\Delta$S	Temperature	Spontaneity
(A)	$+$	$-$	any T	Non spontaneous
(B)	$+$	$+$	low T	spontaneous
(C)	$-$	$-$	low T	Non spontaneous
(D)	$-$	$+$	any T	spontaneous

The incorrect combinations are :

<p>Let's analyze each combination using the Gibbs free energy equation:</p> <p>$\Delta G = \Delta H - T\Delta S$</p> <p>A reaction is spontaneous when $\Delta G < 0.$ </p> <p>Now, consider each case:</p> <p>(A) $\Delta H > 0$ and $\Delta S < 0$ </p> <p><p>Here, $$\Delta G = +\text{(positive)} - T(-\text{(positive)}) = \text{positive} + T\text{(positive)}$$ </p></p> <p><p>This is positive for any temperature. </p></p> <p><p>Thus, the reaction is non-spontaneous for any T, which is correct.</p></p> <p>(B) $\Delta H > 0$ and $\Delta S > 0$ </p> <p><p>Now, $\Delta G = +\text{(positive)} - T\text{(positive)}.$ </p></p> <p><p>For $\Delta G$ to be negative, the temperature has to be <strong>high</strong> enough such that $T\Delta S > \Delta H.$ </p></p> <p><p>The table incorrectly states that the reaction is spontaneous at low T.</p></p> <p>(C) $\Delta H < 0$ and $\Delta S < 0$ </p> <p><p>In this case, $$\Delta G = -\text{(positive)} - T(-\text{(positive)}) = -\text{(positive)} + T\text{(positive)}.$$ </p></p> <p><p>At very low temperatures, the term $T\Delta S$ is small, making $\Delta G$ negative (spontaneous). </p></p> <p><p>The table mistakenly indicates that the reaction is non-spontaneous at low T.</p></p> <p>(D) $\Delta H < 0$ and $\Delta S > 0$ </p> <p><p>Then, $\Delta G = -\text{(positive)} - T\text{(positive)}.$ </p></p> <p><p>This expression is negative at all temperatures, so the reaction is correctly marked as spontaneous.</p></p> <p>Thus, the incorrect combinations are:</p> <p><p>(B): It should be spontaneous at high T, not low T.</p></p> <p><p>(C): It should be spontaneous at low T, not non-spontaneous.</p></p> <p>Therefore, the incorrect combinations are (B) and (C) only.</p> <p>The correct answer is Option D.</p>