The formation of gas at the surface of tungsten due to adsorption is a reaction of which order?

The decomposition of $NH_3$ on $Pt$ surface is a zero order reaction. If the value of rate constant is $2 \times 10^{-4} \ mol \ L^{-1} \ s^{-1}$,the rates of appearance of $N_2$ and $H_2$ are respectively:

Write the rate equation for the reaction $2A + B \to C$ if the order of the reaction is zero.

Derive an expression to calculate the time required for the completion of a zero order reaction.

For a zero-order reaction $A \rightarrow \text{Product}$,the half-life is $1 \ h$. If the initial concentration of reactant $A$ is $2.0 \ mol \ L^{-1}$,how many hours will it take for the concentration to decrease from $0.50 \ mol \ L^{-1}$ to $0.25 \ mol \ L^{-1}$?

Which of the following is correct with respect to the graph given?
$\begin{aligned} & [R]=\text{Concentration at time } t \\ & [R]_0=\text{Initial concentration} \end{aligned}$