A → product (First order reaction). Three sets of experiment were performed for a reaction under similar experimental conditions: Run 1 ⇒100 mL of 10 M solution of reactant A Run 2 ⇒200 mL of 10 M so…

Question

A → product (First order reaction). Three sets of experiment were performed for a reaction under similar experimental conditions:
Run

1 \Rightarrow 100 mL

of 10 M solution of reactant A
Run

2 \Rightarrow 200 mL

of 10 M solution of reactant A
Run

3 \Rightarrow 100 mL

of 10 M solution of reactant

A + 100 mL

of

H_{2} O

added.
The correct variation of rate of reaction is

Accepted Answer

Correct answer: C. (c) For a first-order reaction, rate =k [A ], where rate is directly proportional to reactant concentration. Run 1: 100 mL of 10 M solution Concentration =10M Rate: r_1=k 10 Run 2: 200 mL of 10 M solution Concentration remains 10 M (increasing volume doesn't change concentration) Rate: r_2=k 10 Therefore r_1=r_2 Run 3: 100 mL of 10 M solution +100 mL of H_2O Total moles of A=10M 0.1 L=1 mol Total volume =0.2 L New concentration =1 mol/0.2 L=5M Rate: r_3=k 5 Therefore r_3<r_1=r_2

Solution

More Chemical Kinetics PYQs