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

If the slope of a line of the graph between dissociated concentration of reactant $([A]_0 - [A]_t)$ and time ($t$ in $min$) for a zero order reaction is $0.02 \ mol \ L^{-1} \ min^{-1}$,then calculate the initial concentration of reactant $([A]_0)$,if after $30 \ min$ its concentration $([A]_t)$ is $0.05 \ mol \ L^{-1}$. (in $M$)

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?

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

What is the concentration (in $mol \ L^{-1}$) of the product $B$ after $20 \ s$ in the following reaction? Given that $A \longrightarrow 3B$,rate $= k[A]^0$. The data is provided in the table below:
| Time $(s)$ | Concentration of reactant $A$ $(mol \ L^{-1})$ |
| :--- | :--- |
| $0$ | $0.1$ |
| $15$ | $0.05$ |
| $20$ | $0.1 - x$ |

Which graph represents a zero order reaction $[A_{(g)} \to B_{(g)}]$?