If $c_o$ is the initial concentration of the reactant,what will be the half-life period for a zero-order reaction?

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 $A$ $(mol \ L^{-1})$ |
| :--- | :--- |
| $0$ | $0.1$ |
| $15$ | $0.05$ |
| $20$ | $0.1 - x$ |

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

The reaction $2X \to B$ is a zeroth order reaction. If the initial concentration of $X$ is $0.2 \ M$,the half-life is $6 \ h$. When the initial concentration of $X$ is $0.5 \ M$,the time required to reach its final concentration of $0.2 \ M$ will be ........ $hr$.

The unit of velocity constant in case of zero order reaction is

For a zero order reaction,the plot of concentration of reactant $vs$ time is (Hint: Consider the intercept on the concentration axis)