Hydrogenation of vegetable oil in the presence of Raney Nickel is an example of what?

In aqueous solution,$Na_2SO_3$ is oxidized by air,but $Na_3AsO_3$ is not. However,when air is passed through a solution containing both $Na_2SO_3$ and $Na_3AsO_3$,both are oxidized. This is an example of:

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

In which of the following processes is a catalyst $NOT$ used?

What is the role of desorption in the process of catalysis?

Which statement from the following about nanomaterials is $NOT$ correct?