Question

The rate of an elementary reaction is directly proportional to:

• A. molarities of the reactants raised to their stoichiometric coefficient
• B. normalities of the reactants raised to their stoichiometric coefficient
• C. molarities of the reactants raised to their stoichiometric coefficient
• D. mole fractions of the reactants raised to their stoichiometric coefficient

Answer 1

The correct option is A molarities of the reactants raised to their stoichiometric coefficient

The rate of chemical reaction is directly proportional to the product of the molar concentration of reactants raised to the power of their stoichiometric coefficient.
For example,
For the reaction :
$aA+bB\rightleftharpoons cC+dD$

Rate of reaction $\propto [A{]}^a\times [B{]}^b$
where , $\left[A\right]$ and $\left[B\right]$ are the molar concentration (Molarity) of A and B respectively.
Therefore, rate is directly proportional to the molarity of reactants raised to their stoichiometric coefficient.