Substance X used for whitewashing
Substance X in the question is Calcium oxide also called as “Quick lime”.
Calcium oxide reacts with water and form calcium hyroxide and relases energy as heat. Calcium hydroxide is also called as “slaked lime”.
Checmical reactions and equations
Activity 1.8 Ncert Science class 10
Silver chloride decomposition in the presence of light.
Activity 1.7 Ncert Science class 10
The activity asks to electrolyse water using a 6-volt battery and check the volume of gases liberated at anode and cathode. The activity also asks to bring the gas at the flame and see what happens.
Activity 1.6 Ncert Science class 10
Procedure: The question ask for heating lead nitrate into a test tube filled with boiling water.
Observation: A yellow precipitate of lead oxide is formed with evolution of brown nitrogen di oxide gas which has irritating smell