Answer:
B: increase.
Explanation:
When we are considering two gases A and B in a container at room temperature .
We have to find the change on rate of reaction when the number of molecules of gases A is doubled
Let [A]=a and [B]=b
A+B product
Rate of reaction
We know that concentration is increases with increase in number of moles
When the number of molecules of gases A is doubled then concentration of gases A increases.
Therefore ,[A]=2a
Rate of reaction
Hence, the rate of reaction is 2 times the initial rate of reaction.Therefore, the rate of reaction will increase when the number of molecules of gases A is doubled.
Answer: B: increase.