What is the unit of $K$ for a zero-order reaction?

The rate constant,$k$ of a zero order reaction $2 NH_{3(g)} \xrightarrow[1130 \ K]{Pt} N_{2(g)} + 3 H_{2(g)}$ is $y \times 10^{-4} \ mol \ L^{-1} \ s^{-1}$. The rate of formation of hydrogen (in $mol \ L^{-1} \ s^{-1}$) is

The half-life for a zero order reaction having $0.02 \; M$ initial concentration of reactant is $100 \; s$. The rate constant (in $mol \; L^{-1} s^{-1}$) for the reaction is

If the rate of a reaction is equal to the rate constant,what is the order of the reaction?

The half-life of a zero order reaction $A \rightarrow \text{products}$ is $0.5 \ hr$. The initial concentration of $A$ is $4 \ mol \ L^{-1}$. How much time (in $hr$) does it take for its concentration to come from $2.0 \ mol \ L^{-1}$ to $1.0 \ mol \ L^{-1}$?

Give examples of zero order reactions.