Question

When the concentration of a reactant in reaction $A\to B$ is increased by 8 times but rate increases only 2 times, the order of the reaction would be:

• A. 2
• B. 1/3
• C. 4
• D. 1/2

Answer 1

Answer: (B)

1/3

$r_1=k[A{]}^n$

$r_2=2r_1=k[8A{]}^n$

$\therefore \frac{2r_1}{r_1}=(8{)}^n$
$(2{)}^1=(2{)}^{3n}$

$\therefore 3n=1$

$n=\frac{1}{3}$