Which of the following statements is correct about a zero order reaction?

The rate constant of a zero order reaction is $2.0 \times 10^{-2} \ mol \ L^{-1} \ s^{-1}$. If the concentration of the reactant after $25 \ s$ is $0.5 \ M$,then find the initial concentration of the reactant. (in $M$)

Give examples of zero order reactions.

The time for the half-life period of a certain reaction $A \rightarrow \text{Products}$ is $1 \ hr$. When the initial concentration of the reactant $A$ is $2.0 \ mol \ L^{-1}$,how many hours does it take for its concentration to decrease from $0.50 \ mol \ L^{-1}$ to $0.25 \ mol \ L^{-1}$ if it is a zero-order reaction?

For the reaction,$A \rightarrow$ products,if the graph of $[A]$ vs time gives a straight line,predict the order of the reaction.

If doubling the initial concentration of reactant doubles $t_{1/2}$ of reaction,the order of reaction is