Question

For the reaction A+B+C→D+E, the initial reaction rate was measured for various initial concentrations of reactants. The following data were collected:

Trial	[A] (M)	[B] (M)	[C] (M)	Initial rate (M/s)
1	0.30	0.30	0.30	9.0×10−5
2	0.30	0.30	0.90	2.7×10−4
3	0.60	0.30	0.30	3.6×10−4
4	0.60	0.60	0.30	3.6×10−4

What is the reaction order with respect to A?

What is the reaction order with respect to B?

What is the reaction order with respect to C?

Express your answer as an integer.

please answer!

Answer 1

CONCEPT; Osereve the effect of change in concentration of a reactants (Other reactant concentration must be constant) on rat of reaction.

(A) Observe trial 1 and 3. In trial 1 the concentration of all the reactant is 0.3M. But in trial 3 the concentration of A is doubled to 0.6M but the concentration of other reactants is not changed. So any change in initial rate is due to change in concentration of A.

In trial 1 the initial rate is 9.0×10⁻⁵M/s

In trial 3 the initial rate is 3.6×10⁻⁴M/s

rate has increased by four fold by doubling the concentration of A. ( 3.6×10⁻⁴ / 9.0×10⁻⁵ = 4)

Hence order w.r.t A is 2 only then rate can increase by 4 times.

rate = k [A]²

(B) Observe the trial 3 and 4. Concentration of B is doubled from 0.3 (intrial 3) to 0.6 ( intrial 4). But the rate remains constant 3.6×10⁻⁴M/s. Hence the order w.r.t B is 0.

rate = k[A]²[B]⁰

(C) Observe the trial 1 and trial 2. The concentration of C is tripled from 0.3M to 0.9M. The rate changes from 9.0×10⁻⁵M/s to 2.7×10⁻⁴M/s. Hence reactin has increased by 3 fold. Rate has also tripled. Hence the order w.r.t. C is 3.

Rate = k[A]²[B]⁰[C]¹

Rate = k[A]²[C]¹