The S-block Elements

$Be{\left(OH\right)}_2$ 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

Li⁺ has the largest size in aqueous solution due to its high polarizing power.

It does not contains 2^nd most abundant element by weight in earth crust because that is Si Calgon -> Na₂ [Na₄ (PO₃)₆]

$\underset{}{\overset{Watersoluble}{\to }}2N{a}^{+}{\left[N{a}_4{\left(P{O}_3\right)}_6\right]}^{2-}$

$\underset{}{\overset{C{a}^{2+}}{\to }}2N{a}^{+}{\left[N{a}_{2}Ca{\left(P{O}_3\right)}_6\right]}^{2-}$

Baking soda = NaHCO₃

Washing soda = Na₂CO₃. 10H₂O

Caustic soda = NaOH

Due to high crystallity Be has the highest M.P.

Be = 1560 K

Mg = 925 K

Ca = 1120 K

Sr = 1062 K

Baking soda = NaHCO₃

Washing soda = Na₂CO₃. 10H₂O

Caustic soda = NaOH

B₂H₆ has 4 2 c -2e bonds and 2 3c-2e bonds.

Bridging (B-H) bonds have more value of bond- length then terminal (B – H) bonds

Bridging bonds are in one plane, but terminal bonds are in perpendicular plane.

Due to presence of (3c-2e) bonds, it behaves as electrons deficient and prone to get attached by  lewis  base.

$3NaB{H}_4+4B{F}_3\underset{}{\overset{\Delta }{\to }}3NaB{F}_4+2B_2{H}_6$

Due to higher extent of polarization by Li⁺ and Mg²⁺, LiCl and Mgcl₂ have covalent character. Therefore they are soluble in ethanol.

 Due to very high value of lattice energy, LiF is having very less solubility in water.

The blue color of the solution is due to the ammoniated electron which absorbs energy in infrared region of light