Instantaneous Rate
The rate of a reaction at one particular moment, given by the gradient of the concentration–time curve at that point.
Formula / equation
rate = d[A]/dt
Unit
mol/(L·s)
In depth
Instantaneous rate is found by drawing a tangent to the concentration–time graph or by differentiating a fitted equation. Its value at time zero, the initial rate, is especially useful because no products have yet accumulated to complicate the kinetics through reverse reaction.
Examples in the real world
Taking the tangent gradient at t = 30 s on a plot of reactant concentration against time.