Which of the following reactions requires a catalyst?

$A$ catalyst is used:

Which of the following represents homogeneous catalysis?

Which one of the following acts as an autocatalyst during the titration of $KMnO_4$ and oxalic acid in the presence of dilute $H_2SO_4$?

Which of the following general reactions is an example of heterogeneous catalysis?

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

List-$I$	List-$II$
$A$. $4NH_{3(g)} + 5O_{2(g)} \rightarrow 4NO_{(g)} + 6H_2O_{(g)}$	$I$. $NO_{(g)}$
$B$. $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$	$II$. $H_2SO_{4(l)}$
$C$. $C_{12}H_{22}O_{11(aq)} + H_2O_{(l)} \rightarrow C_6H_{12}O_6 + C_6H_{12}O_6$	$III$. $Pt_{(s)}$
$D$. $2SO_{2(g)} + O_{2(g)} \rightarrow 2SO_{3(g)}$	$IV$. $Fe_{(s)}$

Choose the correct answer from the options given below.