For the reaction $CH_3COOCH_3 + H_2O \xrightarrow{H^{+}} CH_3COOH + CH_3OH$,the progress of the reaction is followed by:

Assertion : The rate of the reaction is the rate of change of concentration of a reactant or a product.
Reason : Rate of reaction remains constant during the course of reaction.

Which of the following units is used to express the rate of a reaction?

$5 Br^{-}_{(aq)} + BrO^{-}_{3(aq)} + 6 H^{+}_{(aq)} \rightarrow 3 Br_{2(aq)} + 3 H_{2}O_{(l)}$
The rate of consumption of $H^{+}$ is $x \ mol \ L^{-1} \ s^{-1}$.
$(a)$ What is the rate of consumption of $Br^{-}$?
$(b)$ What is the rate of formation of $Br_{2}$?

For the reaction $4NH_3 + 5O_2 \to 4NO + 6H_2O$,if the rate of disappearance of $NH_3$ is $3.6 \times 10^{-3} \ mol \ L^{-1} \ s^{-1}$,what is the rate of formation of $H_2O$?

For a chemical reaction $4 A + 3 B \rightarrow 6 C + 9 D$,the rate of formation of $C$ is $6 \times 10^{-2} \ mol \ L^{-1} \ s^{-1}$ and the rate of disappearance of $A$ is $4 \times 10^{-2} \ mol \ L^{-1} \ s^{-1}$. The rate of reaction and the amount of $B$ consumed in an interval of $10 \ s$,respectively,will be: