CHEMISTRY [2 Mark Question Answer]

The change in the colour of reactants during a chemical reaction two examples –
1. The type of reaction where one atom or a set of atoms is replaced with another atom within the same molecule is called a displacement reaction.
2. For example, when silver nitrate is reacted with copper, the copper displaces the silver from the silver nitrate solution and forms a copper nitrate solution.

The evolution of a gas during a chemical reaction two examples -
• electricity is passed through Sodium chloride solution, Sodium chloride decomposes into Sodium and, Chlorine gas is evolved.
• When Zinc is placed in Sulphuric acid, Zinc is more reactive than Hydrogen displaces it from the acid, and forms zinc sulfate and hydrogen gas.