|Class 12 Chemistry Chemical Kinetics||Instantaneous rate of reaction|
Instantaneous rate of reaction
The ratio of change in concentration in chemical reaction to the time period is termed as instantaneous rate of the reaction.
-d[R]/dt = change in chemical concentration over short period of time/ the short time elapsed = (mol/litre) / time
It can be calculated from the slope of the tangent on a concentration- time graph.
For example, consider the following graph.
The rate of reaction at t = 40s in the above graph can be calculated by following method:
Rate of reaction = gradient of the tangent at 40s = (120-70)/(65-5) = 50/60= 0.83 cm3s-1