Question

If the volume of closed vessel in which the following simple reaction is carried out is reduced to one third of Original volume the rate of reaction becomes

2NO(g) + O₂(g)--->2NO₂(g)

A.One third
B.Three times
C.Nine times
D.Twenty seven times

Answer 1

By reducing the volume of a closed vessel to one third, the rate of the reaction 2NO(g) + O₂(g) → 2NO₂(g) increases twenty-seven times because the concentration of NO is squared due to its second-order nature, and the concentration of O₂ is first-order.

Step-by-step explanation:

When the volume of a closed vessel is reduced to one third of its original volume, the concentration of gases increases. The reaction described is 2NO(g) + O₂(g) → 2NO₂(g). Given that the reaction is second-order with respect to NO and first-order with respect to O₂, the rate of reaction is proportional to the concentration of NO squared and to the concentration of O₂.

By reducing the volume to one third, the concentration of each gas is tripled. Therefore, the reaction rate for NO would increase by 3² or 9 times, and O₂ being first-order, triples the rate. Therefore, the new rate of reaction becomes 9 (due to NO) times 3 (due to O₂), which equals 27 times the original rate. Hence, the correct answer for this reaction rate change is twenty-seven times.