Question

Which of the following are the correct statements regarding the catalyzed and uncatalyzed reactions at constant temperature?

• A. Catalyzed reaction does not alter $\Delta H$ of the reaction
• B. At constant temperature, $\Delta G^0$ of the catalysed and uncatalyzed reaction is same
• C. Catalyzed reaction alters equilibrium constant even at constant temperature
• D. Catalysed reaction alters $r_f$ and $r_b$ values equally at constant temperature

Answer 1

Answer: (A), (B), (D)

The correct options are
A Catalyzed reaction does not alter $\Delta H$ of the reaction
B At constant temperature, $\Delta G^0$ of the catalysed and uncatalyzed reaction is same
D Catalysed reaction alters $r_f$ and $r_b$ values equally at constant temperature

The characteristics of a catalyst are as follows:

i) A catalyst remains unchanged chemically at the end of reaction, however, its physical state may change.

ii) A catalys can never initiate a chemical reaction. It simply influences the rate of reaction.

iii) A small quantity of catalyst is sufficient to influence the rate of reaction e.g. $1$ g atom of Platinum is sufficient to catalyse $108$ litres of $H_2{O}_2$ decomposition.

iv) A catalyst does not influence the equilibrium constant of reaction. It simply helps in attaining equilibrium earlier. It alters the rate of forward & backward reactions equally.

v) Catalyst’s activity is more or less specific. A catalyst for one reaction is not necessary to catalyse the another reaction.

A catalyst does not alter $\Delta H$ of the reaction. At constant temperature, $\Delta G^o$ of the catalysed and uncatalysed reaction remains the same. Also, catalysed reaction alter $r_f$ and $r_b$ values equally at constant temperature.