Below,some catalysts and corresponding processes/reactions are matched. The mismatch is

Give information about important features of solid catalysts.

Which of the following reactions requires a catalyst?

Platinised asbestos helps in the formation of $SO_3$ from $SO_2$ and $O_2$. But,if even a small amount of $As_2O_3$ is present,the platinised asbestos does not help in the formation of $SO_3$. $As_2O_3$ acts here as

For the following Assertion and Reason,the correct option is
Assertion : For hydrogenation reactions,the catalytic activity increases from Group $5$ to Group $11$ metals with maximum activity shown by Group $7-9$ elements.
Reason : The reactants are most strongly adsorbed on Group $7-9$ elements.

$2 SO_{2(g)} + O_{2(g)} \stackrel{V_{2}O_{5}}{\rightleftharpoons} 2 SO_{3(g)}$ is an example of