This is the amusing moment a science experiment amazed pupils in China.

Two schoolgirls conducted a chemical kinetics experiment by adding two distinct solutions into a large graduated cylinder in Sichuan on April 1.

Footage shows the stunning moment of a dynamic colour shift during an iodine clock reaction.

The students can be seen pouring the liquid substances into the glass container, while the crowd watches in awe, reacting to the mesmerizing transformation.

The mixtures triggered the liquid to oscillate between deep yellow and deep blue, with the colours changing multiple times.

The iodine clock reaction is a classic chemical demonstration used to study reaction kinetics. It involves a series of redox reactions where iodine is produced and immediately reacts with starch, forming a starch-iodine complex that creates the visible colour changes.

The timing of the colour shifts depends on the concentrations of the reactants and the reaction conditions, allowing scientists to explore the factors that influence reaction rates.

The solutions used typically include hydrogen peroxide, potassium iodate, and manganese sulfate. Hydrogen peroxide serves as an oxidizing agent, while iodate ions are reduced to iodine through a catalytic process involving manganese ions.

This experiment has become a popular way to illustrate concepts in physical chemistry and reaction dynamics.