The catalyst used in the manufacture of methanol from water gas is

When $KMnO_4$ solution is added to hot oxalic acid solution,the decolourisation is slow in the beginning but becomes instantaneous after sometime. This is because

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

$A$ catalyst is a substance that . . . .

Which catalyst is used in the oxidation of $SO_2$ to $SO_3$?

Give information about Homogeneous catalysis and Heterogeneous catalysis.