NEET levelSingle correct optionDifficulty 1 of 3ck205
On a plot of concentration of a reactant against time, the instantaneous rate at time t is obtained from
Athe slope of the straight line joining the first and last points of the curve
Bthe magnitude of the slope of the tangent drawn to the curve at that time
Cthe area under the curve up to time t
Dthe intercept of the curve on the concentration axis
Answer: B
The instantaneous rate is the limit of −Δc/Δt as Δt→0, i.e. −dc/dt. Graphically this is the magnitude of the slope of the tangent at t; a chord gives only an average rate.