Which of the following reaction is used in white washing of walls?
(a) 2Ca + O2 → 2CaO
(b) CaO + H2O → Ca(OH)2
(c) Ca(OH)2 + CO2 → CaCO3 + H2O
(d) Ca(OH)2CaO + H2O
Answers
Answer:
I think c is the right answer
Answer:
When looking at the options that you have provided the correct answer would be….Option C.
Explanation:
Now as You are asking the chemical reaction that is responsible for offering the walls with its whitish looks when white washing the walls. This is a simple question.
The moment we white wash the walls, there are actually two different reactions that are taking place. In the first reaction the slaked lime is mixed with water to form what is known as quick lime. This is one of the reactions when Calcium oxide is mixed with water to form Calcium Hydroxide and Heat is released.
The reaction can be written as given below.
CaO + H2O -------- Ca(OH)2 + Q.
Now this is just the preparation reaction and so it would not be right to say that it is complete reaction that offers whiteness to the walls. The solution that is prepared which is Slaked lime is used on the walls.
The solution is a white washing solution.
The second part of the reaction takes place once the slaked lime is applied to the walls. This second part of the reaction is what offers the walls with perfect white color.
Here Calcium hydroxide that is formed in the first part of the reaction Ca(OH)2 is the chemical substance that actually reacts with the Carbon dioxide gas present in the surrounding air. The moment this reaction takes place a single thin layer of what is called as Calcium carbonate is formed. This calcium carbonate offers the walls with whitish looks.
So the correct reaction would be Ca(OH)2 + CO2 ----- CaCO3 + H2O.
When looking at the options that you have provided the correct answer would be….Option C.