\textbf{216.} The activation energy of the reaction: $\mathrm{N_2(g) + O_2(g) \rightarrow 2NO(g)}$, without a catalyst is 381 and $-181$ kJ/mol. If a catalyst is used instead of an automobile catalytic converter, the activation energy of the reaction decreases to 280 kJ/mol. Which statement about it is correct?
\begin{enumerate}
\item Using a catalyst, the reaction enthalpy and energy content of the products decrease by approximately 25 percent.
\item Without a catalyst and using a catalyst, the energy content of the reactants is greater than that of the products.
\item In this reaction, the products are more stable than the reactants, and using a catalyst causes more heat to be transferred to the environment.
\item Using a catalyst, the rate of exit of oxygen from the automobile increases, because the activation energy for the conversion of reactants to products decreases.
\end{enumerate}
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\textbf{Space for calculations}
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