2A—>B+C indicates the reaction

Question

2–>B+C

Two trials of the above reaction are run. The concentration of A in the second reaction is twice that in the first. It is found that the initial rate of reaction in the first trial is the same as that in the second trial. This indicates that the reaction is?

1. zero order in [A]
2. first order in [A]
3. second order in [A]
4. third order in [A]

Answer 1

Since you doubled the [A] and the rate remained the same, this tells us the reaction is independent of [A] and so it is zero order in [A]. Choice #1 is correct.