Question

For a reaction A +B → C, the experimental rate law is found to be R=k[A]^1[B]^1/2. Find the rate of the reaction when [A] = 0.5 M, [B] = 0.1 M and k=0.03.

(a) 4.74 × 10^-2 (L/mol)^1/2 s^-1

(b) 5.38 × 10^-2 (L/mol)^1/2 s^-1

(c) 5.748 × 10^-2 (L/mol)^1/2 s^-1

(d) 4.86 × 10^-2 (L/mol)^1/2 s^-1

I have been asked this question by my school teacher while I was bunking the class.

Enquiry is from Rate of a Chemical Reaction topic in chapter Chemical Kinetics of Chemistry – Class 12

Answer 1

Correct option is (a) 4.74 × 10^-2 (L/mol)^1/2 s^-1

The best I can explain: Given, [A] = 0.5 M, [B] = 0.1 M and k= 0.03

From the rate law it is evident that the order of the reaction is 1+ 0.5 = 1.5 = \(\frac{3}{2}\)

Therefore the unit of k= (mol L^-1)^1-1.5 s^-1 = (L/mol)^1/2 s^-1

R= k[A]^1[B]^1/2 = 0.03 × 0.5 × 0.1^1/2 = 4.74 × 10^-2(L/mol)^1/2 s^-1.