Which function of $[X]$ plotted against time will give a straight line for a second order reaction? $X \to \text{Product}$

The reaction $2A + B_{2} \rightarrow 2AB$ is an elementary reaction. For a certain quantity of reactants,if the volume of the reaction vessel is reduced by a factor of $3,$ the rate of the reaction increases by a factor of $.....$. (Round off to the Nearest Integer).

For the reaction $2 NO_{(g)} + Cl_{2_{(g)}} \rightarrow 2NOCl_{(g)}$,when the concentration of $Cl_2$ is doubled,the rate of the reaction becomes twice the original rate. When the concentration of $NO$ is doubled,the rate becomes four times the original rate. What is the overall order of the reaction?

The mechanism of the reaction $A + 2B \to D$ is given by:
$2B \xrightarrow{k} B_2$ [Slow]
$B_2 + A \to D$ [Fast]
The rate law expression,order with respect to $A$,order with respect to $B$,and overall order are respectively:

$A$ student has studied the decomposition of a gas $AB_3$ at $25^{\circ} C$. He obtained the following data.

$p \ (mm \ Hg)$	$50$	$100$	$200$	$400$
Relative $t_{1/2} \ (s)$	$4$	$2$	$1$	$0.5$

The order of the reaction is

What is the order of reaction for the decomposition of gaseous acetaldehyde?