Question

How is the progress of a reaction monitored for its kinetic study?

Answer 1

The progress of a reaction for kinetic study is monitored by measuring the change in concentration of a reactant or product over time. This helps determine the rate of reaction and the rate law.

Common Methods to Monitor Reaction Progress:

1. Titration: It is used when a reactant or product can react with a standard solution. At regular intervals, small samples (aliquots) are withdrawn, quenched (if needed), and titrated. Example: Acid-base titration in ester hydrolysis.
2. Spectrophotometry: Measures absorbance of light at a specific wavelength. Works if one of the species (reactant or product) is coloured. Example: Decomposition of potassium permanganate.
3. Conductometry: Monitors change in electrical conductivity of the reaction mixture. Useful if ionic species are involved and their concentrations change. Example: Precipitation of AgCl from AgNO₃ and NaCl.
4. Mass change: Measures loss of mass when a gaseous product escapes. Example: Thermal decomposition of CaCO₃ to CaO and CO₂.