Chemistry

Copolymer is the polymer formed by two or more monomers having multiple bonds.

Buna – S, PHBV and butadiene – styrene are copolymers. Neoprene is homopolymer.

$R-N{H}_2\underset{273K}{\overset{HN{O}_2\left(aq.\right)}{\to }}R-\stackrel{\oplus }{N_2}\underset{298K}{\overset{H_{2}O/-N_2\uparrow }{\to }}R-OH$

1° aliphatic amine           Diazonium salt                Alcohol

In thin layer chromatography, the spots of colourless compounds, which are invisible to eyes can be detected by putting the plate under UV light.

Another detection technique is to place the plate in a covered jar containing I₂ (s). Sometimes an appropriate reagent may also be sprayed on the plate, ninhydrin in case of amino acids

DDT, organophosphates and dieldrin are pesticides.

 ${\left[Ni{\left(CN\right)}_4\right]}^{2-}$

CN is strong field ligand

$N{i}^{2+}=4s^{0}3d^8$

Here; ${\left[Ni{\left(CN\right)}_4\right]}^{2-}$ is square planar and diamagnetic.

$\left[Ni{\left(CO\right)}_4\right]$

Ni = 4s²3d⁸Co is strong field ligand.

Here ; $\left[Ni{\left(CO\right)}_4\right]$ is tetrahedral and diamagnetic

${\left[Ni{\left(CN\right)}_4\right]}^{2-}$ has 3d⁸ configuration while $\left[Ni{\left(CO\right)}_4\right]$ has 3d¹⁰ configuration.

Valence shell electronic configuration of Eu in +2 O.S is,

$E{u}^{2+}=6s^{0}4f^7$                

It has half filled f-sub shell and stable.

Pentavalent oxides of group – 15 elements, E₂O₅ is more acidic than trivalent oxides, E₂O₃ of the same element.

Acidic strength of trivalent oxides decreases down the group as metallic strength increases.

N₂ gas is obtained by thermal decomposition of Ba (N₃)₂ as,

$Ba{\left(N_3\right)}_2\underset{}{\overset{\Delta }{\to }}Ba+3N_2\uparrow$

$CuO+H_2\to Cu+H_{2}O$