Chemical Kinetics · Question 43

Consider an elementary reaction A(g) + B(g) C(g) + D(g) If the volume of reaction mixture is suddenly reduced to 13 of its initial volume, the reaction rate will become 'x' times of the original reaction rate. The value of x is :

1. 3
2. 9
3. 13
4. 19

Answer

(2) 9

Solution

For an elementary reaction the rate law follows the stoichiometry: r = k[A][B]

Reducing the volume to 13 (same number of moles) makes each concentration 3 times:

r' = k(3[A])(3[B]) = 9k[A][B]

x = r'r = 9

Answer: (2)