Chemistry

Electronegativity generally decreases as we move down the group but Pb has higher electronegativity than Sn.

C non-metal

Si and Ge->metalloids

Sn and Pb->metals

E.N. of Sn 1.8, Pb = 1.9

Na+ C + N + S ®NaSCN

Fe³⁺ + SCN^– $\stackrel{}{\to }$ $\underset{Bloodred}{{\left[Fe\left(SCN\right)\right]}^{2+}}$

(A) Fluorspar                     –    CaF₂

(B) Cryolite                 –    Na₃ [AlF₆]

(C) Bauxite                 –    Al₂O₃.2H₂O

(D) Dolomite              –    MgCO₃.CaCO₃

$p_{H_2}=P_T{\chi }_{H_2}$  (P_T = total pressure)

(  ${\chi }_{H_2}$ = mole fraction of H₂)

$p_{O_2}=P_T{\chi }_{O_2}$ ( ${\chi }_{O_2}$  = mole fraction of O₂)

$\frac{p_{H_2}}{p_{O_2}}=\frac{{\chi }_{H_2}}{{\chi }_{O_2}}=\frac{n_{H_2}}{n_{O_2}}$

$n_{H_2}=\frac{1}{2}$  mol

$n_{O_2}=\frac{1}{32}$
$\frac{p_{H_2}}{p_{O_2}}=\frac{1}{2*1}=32$

$\frac{p_{H_2}}{p_{O_2}}=\frac{32}{2}=\frac{16}{1}$

Potassium permanganate in alkaline medium oxidise lodide to lodate.

$2Mn{O}_4^{-}+H_{2}O+I^{\Theta }\stackrel{}{\to }2Mn{O}_2+2O{H}^{\Theta }+I{O}_3^{\Theta }(A)$            

Compound A is  . Therefore, oxidation state of 1is + 5.

For spontaneous process △G < 0

For reversible process △G = 0

Resonance energy is the energy difference between most stable resonating structure andactual structure.