For a zero order reaction $A \longrightarrow \text{product}$,the concentration of $A$ decreases from $0.8 \ mol \ dm^{-3}$ to $0.2 \ mol \ dm^{-3}$ in $6 \ minute$. What is the rate constant of the reaction?

Which of the following is correct with respect to the graph given?
$[R] = \text{Concentration at time } 't'$
$[R]_0 = \text{Initial concentration}$

Consider the reaction $aX \to bY$,for which the rate constant at $30^\circ C$ is $1 \times 10^{-3} \text{ mol L}^{-1} \text{ s}^{-1}$. Which of the following statements are true?
$A$. When concentration of $X$ is increased to four times,the rate of reaction becomes $16$ times.
$B$. The reaction is a second order reaction.
$C$. The half-life period is independent of the concentration of $X$.
$D$. Decomposition of $N_2O_5$ is an example of the above reaction.
$E$. $\ln \frac{[R]_0}{[R]}$ vs time is valid for the above reaction.

For the reaction $A \rightarrow \text{products}$,the graph of $t_{1/2}$ versus $[A]_0$ is given below. The concentration of $A$ at $10 \ \text{minutes}$ is $.......... \times 10^{-3} \ \text{mol L}^{-1}$ $(nearest \ integer)$. The reaction was started with $2.5 \ \text{mol L}^{-1}$ of $A$.

$A$ zero order reaction has a half-life time of $0.2 \ min$. If the initial concentration of the reactant is $0.2 \ mol \ dm^{-3}$,find the rate constant.

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