The main Precautions to be taken in the study of reaction rate for the reaction between potassium iodate $\left({\mathrm{KIO}}_3\right)$ and sodium sulphite $\left({\mathrm{Na}}_2{\mathrm{SO}}_3\right)$ using starch solution as indicator at different concentrations and temperature.
 

1) The concentration of sodium thiosulphate solution should always be less than the concentration of the potassium iodide solution. 

2) Freshly prepared starch solution should be used, since starch may be hydrolyzed to Amylose or Glucose.

3) Experiments should be performed with the fresh solutions of ${\mathrm{H}}_2{\mathrm{O}}_2$ and KI.