A house wife wanted her house to be white washed. She bought 10 kg of quick lime from the market and dissolved in 30 litres of water. On adding lime to the water, she noticed that the water started boiling even when it was not being heated. Give reason for her observation. Write the corresponding equations and name the product formed. [3 MARKS]
A house wife wanted her house to be white washed. She bought 10 kg of quick lime from the market and dissolved in 30 litres of water. On adding lime to the water, she noticed that the water started boiling even when it was not being heated. Give reason for her observation. Write the corresponding equations and name the product formed. [3 MARKS]
Each point: 1 Mark
1. When water is added to quick lime, a suspension of calcium hydroxide, also called slaked lime, is formed.
2. CaO(s)+H2O(l)→Ca(OH)2+Heat
3. Since the reaction is highly exothermic, the solution started boiling although it was not being heated. The suspension of slaked lime is allowed to cool for some time, preferably overnight. It is then decanted and the liquid obtained is used for white washing.
Each point: 1 Mark
1. When water is added to quick lime, a suspension of calcium hydroxide, also called slaked lime, is formed.
2. CaO(s)+H2O(l)→Ca(OH)2+Heat
3. Since the reaction is highly exothermic, the solution started boiling although it was not being heated. The suspension of slaked lime is allowed to cool for some time, preferably overnight. It is then decanted and the liquid obtained is used for white washing.
