Answer the following in brief.
How instantaneous rate of reaction is determined?
Solution
i. To determine the instantaneous rate of a reaction the progress of a reaction is followed by measuring the concentrations of a reactant or product for different time intervals.
ii. The concentration of a reactant or a product is plotted against time.
iii. A tangent drawn to the curve at time t1 gives the rate of the reaction. The slope thus obtained gives the instantaneous rate of the reaction at time t1.
Determination of instantaneous rate
iv. Mathematically the instantaneous rate is expressed by replacing Δ by derivative dc/dt in the expression of the average rate.
Instantaneous rate = `("d"["C"])/"dt"`
v. For a reaction A → B
Instantaneous rate of consumption of A at time t = `-("d"["A"])/"dt"`
Instantaneous rate of the formation of B at time t = `("d"["B"])/"dt"`
Therefore, instantaneous rate of the reaction at time t = `-("d"["A"])/"dt"` = `("d"["B"])/"dt"`
