The S-block Elements

Li⁺ has the highest hydration enthalpy.

Hence it is most hydrated

Therefore, Correct order of hydrated radii is Cs⁺ < Rb⁺ < K⁺ < Na⁺ < Li⁺

Sodium carbonate is a white crystalline solid which exists as a decahydrate,  This is also called washing soda.

Suspension of slaked lime in water is known as milk of lime

Crude sodium chloride obtained by crystallisation of brine solution contains CaSO₄, Na₂SO₄ and MgCl₂

Beryllium salts are easily hydrolysed

Gypsum : CaSO₄ * 2H₂O

$N{H}_3$ is recovered when solution containing $N{H}_{4}Cl$ is treated with $Ca{\left(OH\right)}_2$   (slaked lime).

$2N{H}_{4}Cl+Ca{\left(OH\right)}_2\to 2N{H}_3+CaC{l}_2+H_{2}O$ .

$Ca{H}_2+2H_{2}O\to Ca{\left(OH\right)}_2+2H_2\left(g\right)$

(Hydrolith)

$CaC{O}_3\left(s\right)\to CaO\left(s\right)+C{O}_2\left(g\right)$

1 mol 1 mol

100 g 22.4 L at STP

Volume of ${}_{}$ $C{O}_2$ obtained $=22.4*\frac{25}{100}=5.6L$ $\frac{}{}$ at STP

$Be{\left(OH\right)}_2$ is amphoteric in nature

$Be{\left(OH\right)}_2+2O{H}^{-}\to {\left. [Be{\left(OH\right)}_4\right]}^{2-}$

Suspension of slaked lime in water is known as milk of lime

Crude sodium chloride obtained by crystallisation of brine solution contains CaSO4, Na2SO4 and MgCl2

Beryllium salts are easily hydrolysed 

Gypsum : CaSO₄ . 2H₂O

Plaster of Paris : CaSO₄ .1/2HO₂