Chemistry

Au + NaCN + O₂ → Na [Au (CN)₂]

$Zn+Na\left[Au{\left(CN\right)}_2\right]\to N{a}_2\left[Zn{\left(CN\right)}_4\right]+Au$

$Ais{\left[Au{\left(CN\right)}_2\right]}^{-}andBis{\left[Zn{\left(CN\right)}_4\right]}^{-2}$

 $A{\mathcal{l}}^{+3}$ → number of electrons = 10

Br → number of electrons = 36

$B{e}^{+2}$ → number of electrons = 2

$C{\mathcal{l}}^{-}$ → number of electrons = 18

$L{i}^{+}$ → number of electrons = 2

$S^{-2}$ → number of electrons = 18

K⁺ → number of electrons = 18

O^-2 → number of electrons = 10

Mg⁺² → number of electrons = 10

O^-2 & Mg⁺² are isoelectronic with Al⁺³

Bond strength $\propto$ Bond order

$N_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\sigma }_{2pz}^2$

$O_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\sigma }_{2pz}^2{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\pi }_{2px}^{*1}\equiv {\pi }_{2py}^{*1}$

$C_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2$

$B_2\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^1\equiv {\pi }_{2py}^1$

NO Number of electron = 7 + 8 = 15

B.O. Similar to $N_2^{-}$

$N_2^{-}\to {\sigma }_{1s}^2{\sigma }_{1s}^{*2}{\sigma }_{2s}^2{\sigma }_{2s}^{*2}{\pi }_{2px}^2\equiv {\pi }_{2py}^2{\sigma }_{2pz}^2{\pi }_{2px}^{*1}\equiv {\pi }_{2py}^{*}$

B.O. of N₂ = 3B.O of C₂ = $\frac{8-4}{2}=2$

Removal of e form antibonding molecular orbital increases bond order.

In NO & O₂ has valance e in orbital.

The name of covalent and ionic bonds tell their formation story in small detail. Co- means sharing or coexisting, so whenever there is bond fromation due to sharing of valence electron,  it is known as covalent bond. Similerly, ionic bonds suggest that when a bond formation takes place due to ions, which attract each other, it is considered as ionic bond. Ionic bonds are also known as electrovalent bonds. There are some major differences between Electrovalent and covalent bonds. Chekc the table below:

For more detail related to the chemical bonding in class 11 chemistry read our notes.

Chemical Bonding and Molecular Structure

Ala – Gly – Leu-Ala- Val

Two amino acid units are connected by peptide linkage. So number of peptide linkage = 4.

Number of moles of gas = $\frac{22.4}{22400}=\frac{1}{1000}moles$

Mass of nitrogen = $\left(\frac{1}{1000}*28\right)gm$

% of N in organic compound = $\frac{\left(\frac{28}{1000}\right)}{0.2}*100\mathrm{\%}=14\mathrm{\%}$

In acidic solution

$3\stackrel{+6}{Mn}{O}_4^{2-}+4H^{+}\to 2\stackrel{+7}{Mn}{O}_4^{-}+\stackrel{+4}{Mn}{O}_2+2H_{2}O$

Difference in oxidation state of Mn is product

= 7 – 4 = 3

Baryte – BaSO₄ [Sulphate based ore]

Galena – PbS

Zinc blende – ZnS

Copper pyrite – CuFeS₂