Question

Question 29
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.

Answer 1

(a) The phenomena given in the question is a chemical change because the composition of the product formed is different from the substance taken.
(b) Yes, one can prepare one acidic and one basic solution by using the products formed in the above process.
(i) When CaO dissolves in water it forms calcium hydroxide which is a basic solution.
$CaO\left(s\right)+H_{2}O\left(l\right)\to Ca\left(OH{)}_2\right(aq)$

(ii) When $C{O}_2\left(g\right)$ dissolves in water it forms carbonic acid which is acidic solution.
$C{O}_2\left(g\right)+H_{2}O\left(l\right)\to H_{2}C{O}_3\left(aq\right)$