# NEET Chemistry Hydrogen Questions Solved

Chemical A is used for water softening to remove temporary hardness. A reacts with sodium carbonate to generate caustic soda. When ${\mathrm{CO}}_{2}$ is bubbled through a solution of A, it turns cloudy. What is the chemical formula of A$-$

(A) ${\mathrm{CaCO}}_{3}$

(B) $\mathrm{CaO}$

(C) $\mathrm{Ca}{\left(\mathrm{OH}\right)}_{2}$

(D) $\mathrm{Ca}{\left({\mathrm{HCO}}_{3}\right)}_{2}$

(C). $\mathrm{Ca}{\left(\mathrm{OH}\right)}_{2}$ is used for the softening of temporary hard water.

Difficulty Level:

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