The Determination of the Reaction Rate for the First Step in a Consecutive Reaction A → B → C by Absorbance Measurements Using the Wavelength of the Isosbestic Point of B and C

Kinetic experiments are often followed by spectroscopic measurements in the visible or near ultraviolet region. The advantage is not only that the results can be recorded continuously, which makes very fast reactions accessible, but also that very low concentrations of substrates can be used. This means that only very small amounts are required and, more important perhaps, that reagents can be used in excess. Thus pseudomonomolecular conditions and first-order kinetics often can be achieved easily.