Question

If $C{O}_2$ is passed in excess into lime water, the milkiness first formed disappears due to

• A. reversal of the original reaction
• B. formation of volatile calcium derivative
• C. formation of water soluble calcium bicarbonate
• D. the solution getting heated by exothermic reaction

Answer 1

The correct option is C formation of water soluble calcium bicarbonate

$CaO+C{O}_2\to CaC{O}_3$

$CaC{O}_3+H_2­O+C{O}_2\to Ca(HC{O}_3{)}_2$