The following results are obtained in the hydrolysis of chlorobutane $(C_4H_9Cl)$:

Time $(s)$	$0$	$100$	$200$	$300$	$400$	$700$	$800$
$[C_4H_9Cl]$ $(mol \, L^{-1})$	$0.100$	$0.082$	$0.067$	$0.055$	$0.044$	$0.021$	$0.017$

Calculate the average rate $r_{av}$ of the reaction during different time intervals.

Observe the following reaction: $2 A + B \longrightarrow C$. The rate of formation of $C$ is $2.2 \times 10^{-3} \ mol \ L^{-1} \ min^{-1}$. What is the value of $-\frac{d[A]}{d t}$ (in $mol \ L^{-1} \ min^{-1}$)?

The rate of reaction is expressed as
$+\frac{1}{2}\frac{d[C]}{dt} = -\frac{1}{3}\frac{d[D]}{dt} = +\frac{1}{4}\frac{d[A]}{dt} = -\frac{d[B]}{dt}$
The reaction is:

Find the average rate of formation of $O_{2(g)}$ in the following reaction:
$2 NO_{2(g)} \rightarrow 2 NO_{(g)} + O_{2(g)}$
Given that $\left[-\frac{\Delta[NO_2]}{\Delta t}\right] = x \ mol \ dm^{-3} \ s^{-1}$

For a given chemical reaction $\gamma_{1} A + \gamma_{2} B \rightarrow \gamma_{3} C + \gamma_{4} D$,the rate of appearance of $D$ is $1.5$ times the rate of disappearance of $B$,which is twice the rate of disappearance of $A$. The rate of appearance of $D$ has been experimentally determined to be $9 \, mmol \, dm^{-3} s^{-1}$. Therefore,the rate of reaction is $...... \, mmol \, dm^{-3} s^{-1}$. (Nearest Integer)

For the reaction $2A + B \rightarrow 3C + D$,which of the following does not express the rate of reaction?