7.1.4 Instantaneous Rate of Reaction from a Graph

1. The rate of reaction changes from time to time as the reaction happens.
2. The rate of reaction at a particular time is called the instantaneous rate.
3. The instantaneous rate of a reaction is equal to the gradient of tangent at a particular time.

Rate of reaction = Δ(product) Δ(Time) Δ(Product) = Change of the amount of product Δ(Time) = Change of the time

Example

The graph shows the volume of carbon dioxide gas released over time in a chemical reaction. Find the rate of reaction at t = 40s.

Answer:

Rate of reaction at 40s = gradient of the tangent at 40s

Rate of reaction = 132-48 70-10 =1.4c m 3 s -1