Question

Select the correct statement.

• A. Rate of reaction increases with decrease in concentration of reactants
• B. Rate law or rate equation shows rate of reaction in terms of concentration
• C. Units of rate constant are $mol\, L ^{-1}\, s ^{-1}$
• D. For the reaction, $a A +b B \longrightarrow$ product, if rate $=[A]^{x}$ and $[B]^{y}, a$ and $b$ are always equal to $x$ and $y$

Answer 1

Answer: (B)

Rate of reaction $\propto$ concentration of reactant so rate of reaction decreases with decrease in concentration of reactants. Units of rate constant depend upon the order of reaction.
Rate law expression shows the rate of reaction is terms of concentration.
i.e. $r=[A]^{x}[B]^{y}$
Here, $x$ and $y$ may or may not be equal to stoichiometric coefficients.