Bihar Police Constable Model Paper 1

Carbon dioxide $\left(\mathit{C}{\mathit{O}}_2\right)$ gas turns lime water milky.

• When $\mathit{C}{\mathit{O}}_2$ reacts with $\mathit{C}\mathit{a}{\left(\mathit{O}\mathit{H}\right)}_2$ (lime water) it turns into Calcium Carbonate $\left(\mathit{C}\mathit{a}\mathit{C}{\mathit{O}}_3\right)$ which is a milky color.
• $\mathit{C}{\mathit{O}}_2+\mathit{C}\mathit{a}{\left(\mathit{O}\mathit{H}\right)}_2$  → $\mathit{C}\mathit{a}\mathit{C}{\mathit{O}}_3$ (Milky Calcium Carbonate)
• $\mathit{S}{\mathit{O}}_2$ can also turn Milky when reacting with lime water.
• $\mathit{S}{\mathit{O}}_2+\mathit{C}\mathit{a}{\left(\mathit{O}\mathit{H}\right)}_2$  → $\mathit{C}\mathit{a}\mathit{S}{\mathit{O}}_4$  (Milky Calcium Sulphate)