Consider the following reaction: A → 2C
The average rate of appearance of C is given by Δ[C]/Δt. Comparing the rate of appearance of C and the rate of disappearance of A, we get Δ[C]/Δt = ________ × (-Δ[A]/Δt).

Question

Quizplus · Accepted Answer

The stoichiometry of the reaction indicates that for every one A that disappears, two C appear. Therefore, the rate of disappearance of A is given by (-Δ[A]/Δt) while the rate of appearance of C is given by Δ[C]/Δt. To compare the two rates, we need to find the ratio of the coefficients in the balanced chemical equation, which is 2:1. Therefore, Δ[C]/Δt = 2*(-Δ[A]/Δt), which simplifies to Δ[C]/Δt = -2(Δ[A]/Δt) or, equivalently, Δ[C]/Δt = (-1/2)*(-Δ[A]/Δt). Thus, the answer is A, +2.

Consider the Following Reaction: a → 2C