The reaction a + 2b + c -- > d + 2e is first order in reactant a, first order in b, and second order in c. what is the rate law equation for this reaction?
a) rate = [a][b]2[c]
b) rate = [a][b][c]2
c) rate = [a][b]/2[c]
d) rate = k[a][b][c]2
e) k = [a][b][c]2

Answer : The correct option is, (B)

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

The general reaction is:

The general rate law expression for the reaction is:

where,

a = order with respect to A

b = order with respect to B

R = rate  law

k = rate constant

and = concentration of A and B reactant

Now we have to determine the rate law for the given reaction.

The balanced equations will be:

In this reaction, A, B and C are the reactants and the 1st order of reaction for reactant A, 1st order of reaction for reactant B and 2nd order of reaction for reactant C.

The rate law expression for the reaction will be:

or,

Hence, the correct option is, (B)