Metal atom in the lower oxidation state forms the ionic bond and in the higher oxidation state the covalent bond. because higher oxidation state means small size and great polarizing power and hence greater the covalent character. Hence $$MC{l_2}$$  is more ionic than $$MC{l_4}.$$

The water sample containing $$Mn = 5\,ppm$$   is unsuitable for drinking as the prescribed level for $$Mn$$  in drinking water is $$0.5ppm.$$

When a solution of potassium chromate is treated with an excess of dilute nitric acid. Potassium dichromate and $${H_2}O$$  are formed.
$$\eqalign{ & 2{K_2}Cr{O_4} + 2HN{O_3} \to {K_2}C{r_2}{O_7} + 2KN{O_3} + {H_2}O \cr & {\text{Hence}}\,C{r_2}O_7^ - \,{\text{and}}\,{H_2}O\,{\text{are}}\,{\text{formed}}{\text{.}} \cr} $$

$$_{24}Cr \to 1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}\underbrace {4{s^1}3{d^5}}_{{\text{half - filled}}}$$

In laboratory, manganese $$\left( {II} \right)ion$$   salt is oxidised to permagnate ion in aqueous solution by peroxodi-sulphate.
$$\mathop {2M{n^{2 + }} + {S_2}O_8^{2 - } + 8{H_2}O}\limits_{{\text{peroxodisulphate ion}}} \to 2MnO_4^ - + 10\,SO_4^{2 - } + 16{H^ + }$$

$$KMn{O_4}$$  reacts with $${H_2}S{O_4}$$  to form $$M{n_2}{O_7}$$   which is highly explosive substance.
$$2KMn{O_4} + {H_2}S{O_4} \to {K_2}S{O_4} + M{n_2}{O_7} + {H_2}O$$

No explanation is given for this question. Let's discuss the answer together.

+4 oxidation state of cerium is also known in solutions.

$$6MnO_4^ - + {I^ - } + 6O{H^ - } \to 6MnO_4^{2 - } + IO_3^ - + 3{H_2}O$$

No explanation is given for this question. Let's discuss the answer together.