The catalyst and promoter respectively used in the Haber's process of industrial synthesis of ammonia are

The following reaction is catalyzed by $Br^-_{(aq)}$: $2H_2O_{2(aq)} \rightarrow 2H_2O_{(l)} + O_{2(g)}$. What type of catalysis is this?

Define the following terms:
$(i)$ Inhibitors
$(ii)$ Catalyst

Which of the following acts as a negative catalyst?

$A$ negative catalyst .......

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: