8.2 Carboxylic acids and their derivative — Chemistry STD 12 Science — Question

1. $ \mathrm{Cu}^{+} \rightarrow \mathrm{Cu}^{2+}+\mathrm{Cu} $
2. $ 3 \mathrm{MnO}_4{^-}+4 \mathrm{H}^{+} \rightarrow 2 \mathrm{MnO}_4{^-}+\mathrm{MnO}_2+2 \mathrm{H}_2 \mathrm{O} $
3. $ 2 \mathrm{KMnO}_4 \rightarrow \mathrm{K}_2 \mathrm{MnO}_4+\mathrm{MnO}_2+\mathrm{O}_2 $
4. $2 \mathrm{MnO}_4{^-}+3 \mathrm{Mn}^{2+}+2 \mathrm{H}_2 \mathrm{O} \rightarrow 5 \mathrm{MnO}_2+4 \mathrm{H}^{+} $

Atomic weight : $Fe =55.85 ; \mathrm{S}=32.0$ $\mathrm{O}=16.00$

$\left[\mathrm{CoCl}\left(\mathrm{NH}_3\right)_5\right]^{2+}, \quad\left[\mathrm{Co}(\mathrm{CN})_6\right]^{3-} \text {, }$

$(A)$                                        $(B)$

$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{3+}, \quad\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{2+}$

$(C)$                                       $(D)$

The correct order of $A$, $B$, $C$ and $D$ in terms of wavenumber of light absorbed is :