Question

Which one of the following values of $\Delta H^o$ represents that the product is least stable?

• A. $-94.0kcal$ ${mol}^{-1}$
• B. $-231.6kcal$ ${mol}^{-1}$
• C. $+21.4kcal$ ${mol}^{-1}$
• D. $+64.8kcal$ ${mol}^{-1}$

Answer 1

Answer: (D)

$+64.8kcal$ ${mol}^{-1}$

The reaction in which the value of $\Delta H>0$ has the energy of products more than that of the reactants.
And the reaction in which the energy of product is much more will have the value of $\Delta H>>0.$
And since, the product with more energy value is less stable, hence the least stable product is the one with maximum value of $\Delta H.$
Hence, answer is option D.