I am following a reaction that catalysed by a catalyst using Hnmr spectra . I have a series of Hnmr spectra with respect to time, and by integration the reactant peak and product peak, I got the molar ratio, then I calculated the conversion vs time curve.

My question is:

How Can I calculate the relative concentration of the product from percentage conversion, or from the data I have, Thus calculate the instantaneous rate of reaction?

P.s. there is no internal standard used during monitoring the reaction.

Many thanks in advance!