Gypsum $CaSO_4 \cdot 2H_2O$ on heating to about $120 \, ^oC$ forms a compound which has the chemical composition represented by

When $CO_2$ is passed into lime water,it turns milky. When an excess of $CO_2$ is passed,the milkiness disappears because:

$Assertion$ $(A)$: Helium and beryllium have similar outer electronic configuration $ns^2$. $Reason$ $(R)$: Both are chemically inert.

Which of the following is least hydrolysed?

Match the compounds in List-$I$ with their chemical formulas in List-$II$ and select the correct answer using the codes given below:
List-$I$ (Compounds) | List-$II$ (Formulas)
$(A)$ Plaster of Paris | $(i) \, CaSO_4 \cdot 2H_2O$
$(B)$ Epsomite | $(ii) \, CaSO_4 \cdot \frac{1}{2} H_2O$
$(C)$ Kieserite | $(iii) \, MgSO_4 \cdot 7H_2O$
$(D)$ Gypsum | $(iv) \, MgSO_4 \cdot H_2O$

What are the products formed when an aqueous solution of magnesium bicarbonate is boiled?