Ncert Solutions Chemistry Class 12th

Cerium exists in two oxidation states (+3) and (+4)

  $\begin{array}{l}C{e}^{+4}+e^{-}\to C{e}^{+3}{E}^0=1.61V\\ C{e}^{+3}+3e^{-}\to Ce{E}^0=-2.336V\end{array}$  

It exist as Ce⁺⁴ and acts like a strong oxidizing agent by gaining electrons

Caprolactum is monomer of nylon-6

Isoprene is polymer of natural rubber

2 – chloro-1,3-butadiene or chloroprene is the polymer of neoprene which is a synthetic rubber

Acrylonitrite is one of the monomer of Buna-N

$C{H}_2=CH-CN$ Acrylonitrile

Freundlich adsorption isotherm

$\frac{x}{m}=k{p}^{1/n}$            

$log\frac{x}{m}=\frac{1}{n}logp+logk$           

Comparing with y = mx + C

so, slope of given graph is $\frac{1}{n}$  whose value varies from 0 to 1.

Sphalerite is ore of zinc consists of ZnS during its concentration group 1 cyanides are used as depressants like NaCN

Major components of gun metal are Cu, Sn and Zn

$AgC\mathcal{l}+2N{H}_3\to \underset{\left(Solublecomplex\right)}{\left[Ag{\left(N{H}_3\right)}_2\right]C\mathcal{l}}$

Blue cupric metaborate is reduced to cuprous metaborate in a luminous flame.

$2Cu{\left(B{O}_2\right)}_2+2NaB{O}_2+C\underset{}{\overset{Luminous}{\to }}2CuB{O}_2+N{a}_2{B}_4{O}_7+CO$            

Cupric metaborate is obtained by heating boric anhydride & copper sulphate in a non-luminous flame as

$CuS{O}_4+B_2{O}_3\underset{}{\overset{Non-LuminiousFlame}{\to }}\underset{Blue}{Cu{\left(B{O}_2\right)}_2}+S{O}_3.$            

Size of hydrated ion $$ $\propto$ $\frac{1}{Ionicmobility}$ $\frac{}{}$

Size of hydrated ions $\propto \frac{1}{Ionicsize}$ $\frac{}{}$

Size of hydrated ions ;  $B{e}^{+2}>M{g}^{+2}>C{a}^{+2}>S{r}^{+2}$ ${}^{}{}^{}{}^{}{}^{}$

Ionic mobility ; $B{e}^{+2}<M{g}^{+2}<C{a}^{+2}<S{r}^{+2}$

Cu is the only element of 3d – series whose M²⁺ / M value is positive because of fact that low hydration enthalpy and high sublimation & ionization enthalpies.