Chemistry

The value of crystal field spilitting energy ${}_{}$ $\left({\Delta }_0\right)$ increases down the group. 5d series member will have more ${}_{}$ ${\Delta }_0$ compared to 3d series or 4d series member.

Unit cell = Hexagonal close packing (hcp)

No. of X in one unit cell = 6

No. of tetrahedral voids in one unit cell = 12

No. of Y in one unit cell = $\frac{2}{3}*12=8$ $\frac{}{}$

Formula => X₆ Y₈ => X₃ Y₄

% of X in unit cell $=\frac{3}{7}*100\mathrm{\%}=43\mathrm{\%}$ $\frac{}{}$

Phosphorous can expand its covalency beyond 4, as it has vacant 3d orbitals. Nitrogen can't expand its covelency beyond 4, as it does not posses vacant 3d- orbitals.

Fire extinguisher contains sodium Bicarbonate (NaHCO3), also known as baking soda.

NaOH is obtained by electrolysis of NaCl. Solution of NaCl using Hg cathode

$\begin{array}{l}Cathode:N{a}^{+}+e\underset{}{\overset{Hg}{\to }}Na-Amalgam\\ Anode:2C{l}^{-}\to C{l}_2+2e\\ 2Na-Amalgam+2H_{2}O\to 2NaOH+2Hg+H_2\end{array}$

$N{i}^{2+}+2dmg\to \left[Ni{\left(dmg\right)}_2\right]\downarrow$ Rosy-red precipitate

In Hall Heroult process electrolysis is carried out using carbon anode. The liberated

O2 at anode reacts with anode.

Cathode : $A{l}^{3+}\left(melt\right)+3ek\to A\mathcal{l}\left(\mathcal{l}\right)$

Anode : $\begin{array}{l}C\left(s\right)+O^{2-}\left(Melt\right)\to CO\left(g\right)+2e\\ C\left(s\right)+2O^{2-}\left(Melt\right)\to C{O}_2\left(g\right)+4e\end{array}$

Net Reaction 2Al2O3 + 3C $4A\mathcal{l}+3C{O}_2$

Penicillin is not a broad spectrum artibiotic and is used to treat only certain infections caused by streptococci and staphylococci such as pneumonia.

$Cellulose\underset{}{\overset{H^{+}/H_{2}O}{\to }}\beta -D-Glucose\underset{Water}{\overset{B{r}_2}{\to }}Gluconicacid$

Kindly consider the following figure