The process in which one of the products acts as a catalyst is known as:

Iron $(III)$ catalyses the reaction between iodide and persulphate ions,in which
$A$. $Fe^{3+}$ oxidises the iodide ion
$B$. $Fe^{3+}$ oxidises the persulphate ion
$C$. $Fe^{2+}$ reduces the iodide ion
$D$. $Fe^{2+}$ reduces the persulphate ion
Choose the most appropriate answer from the options given below:

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A. N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$	$I. Fe_xO_y + K_2O + Al_2O_3$
$B. CO_{(g)} + 3H_{2(g)} \rightarrow CH_{4(g)} + H_2O_{(g)}$	$II. Ni$
$C. CO_{(g)} + H_{2(g)} \rightarrow HCHO_{(g)}$	$III. Cu$
$D. CO_{(g)} + 2H_{2(g)} \rightarrow CH_3OH_{(g)}$	$IV. Cu/ZnO - Cr_2O_3$

Choose the correct answer from the options given below.

Explain the characteristics of enzyme catalysis.

Give information about the utility of catalysts in industries.

What is the role of $MnO_2$ in the decomposition reaction $2KClO_3 \to 2KCl + 3O_2$?