Explanation:

Explanation:

\(\Delta_{0} \propto \dfrac{1}{\lambda}\)
Order of \(\Delta_{0}\) :
\({\left[ {{\text{M(en}}{{\text{)}}_{\text{3}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]^{{\text{4 - }}}}\)
Order of \(\lambda\) (wavelength of absorbed light):
\(\mathop {{{\left[ {{\text{M( en }}{{\text{)}}_{\text{3}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{green}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{orange}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]}^{{\text{4 - }}}}}\limits_{\left( {{\text{red}}} \right)} \)

Explanation:

\[\left. {\begin{array}{*{20}{l}}
{{\text{T}}{{\text{i}}^{{\text{4 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}} \\
{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}{\text{:3}}{{\text{d}}^{{\text{10}}}}} \\
{{\text{S}}{{\text{c}}^{{\text{3 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}}
\end{array}} \right\}{\text{ Completely filled or empty d - orbitals are colourless}}{\text{. }}\]
\(\mathrm{Cr}^{3+}: 3 \mathrm{~d}^{3}\) exhibits colour due to \(\mathrm{d}-\mathrm{d}\) transition.

Explanation:

Conceptual Questions

Explanation:

Aqueous of solution \(\mathrm{CoCl}_{2}\) contains \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) which is pinkish in colour so option (4) is incorrect.
Reduction potential of \(\mathrm{Co}^{3+} \rightarrow \mathrm{Co}^{2+}\) is high so option (2) is incorrect. \(\mathrm{Co}^{2+}\) does not oxidise easily to \(\mathrm{Co}^{3+}\).
It a general case that symmetrial substituted octahedral complexes are less deeper in colour than tetrahedral complexes. So \(\left[\mathrm{CoCl}_{4}\right]^{2-}\) is deep blue in colour.

Explanation:

Explanation:

\(\Delta_{0} \propto \dfrac{1}{\lambda}\)
Order of \(\Delta_{0}\) :
\({\left[ {{\text{M(en}}{{\text{)}}_{\text{3}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]^{{\text{4 - }}}}\)
Order of \(\lambda\) (wavelength of absorbed light):
\(\mathop {{{\left[ {{\text{M( en }}{{\text{)}}_{\text{3}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{green}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{orange}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]}^{{\text{4 - }}}}}\limits_{\left( {{\text{red}}} \right)} \)

Explanation:

\[\left. {\begin{array}{*{20}{l}}
{{\text{T}}{{\text{i}}^{{\text{4 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}} \\
{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}{\text{:3}}{{\text{d}}^{{\text{10}}}}} \\
{{\text{S}}{{\text{c}}^{{\text{3 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}}
\end{array}} \right\}{\text{ Completely filled or empty d - orbitals are colourless}}{\text{. }}\]
\(\mathrm{Cr}^{3+}: 3 \mathrm{~d}^{3}\) exhibits colour due to \(\mathrm{d}-\mathrm{d}\) transition.

Explanation:

Conceptual Questions

Explanation:

Aqueous of solution \(\mathrm{CoCl}_{2}\) contains \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) which is pinkish in colour so option (4) is incorrect.
Reduction potential of \(\mathrm{Co}^{3+} \rightarrow \mathrm{Co}^{2+}\) is high so option (2) is incorrect. \(\mathrm{Co}^{2+}\) does not oxidise easily to \(\mathrm{Co}^{3+}\).
It a general case that symmetrial substituted octahedral complexes are less deeper in colour than tetrahedral complexes. So \(\left[\mathrm{CoCl}_{4}\right]^{2-}\) is deep blue in colour.

Explanation:

Explanation:

\(\Delta_{0} \propto \dfrac{1}{\lambda}\)
Order of \(\Delta_{0}\) :
\({\left[ {{\text{M(en}}{{\text{)}}_{\text{3}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]^{{\text{4 - }}}}\)
Order of \(\lambda\) (wavelength of absorbed light):
\(\mathop {{{\left[ {{\text{M( en }}{{\text{)}}_{\text{3}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{green}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{orange}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]}^{{\text{4 - }}}}}\limits_{\left( {{\text{red}}} \right)} \)

Explanation:

\[\left. {\begin{array}{*{20}{l}}
{{\text{T}}{{\text{i}}^{{\text{4 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}} \\
{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}{\text{:3}}{{\text{d}}^{{\text{10}}}}} \\
{{\text{S}}{{\text{c}}^{{\text{3 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}}
\end{array}} \right\}{\text{ Completely filled or empty d - orbitals are colourless}}{\text{. }}\]
\(\mathrm{Cr}^{3+}: 3 \mathrm{~d}^{3}\) exhibits colour due to \(\mathrm{d}-\mathrm{d}\) transition.

Explanation:

Conceptual Questions

Explanation:

Aqueous of solution \(\mathrm{CoCl}_{2}\) contains \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) which is pinkish in colour so option (4) is incorrect.
Reduction potential of \(\mathrm{Co}^{3+} \rightarrow \mathrm{Co}^{2+}\) is high so option (2) is incorrect. \(\mathrm{Co}^{2+}\) does not oxidise easily to \(\mathrm{Co}^{3+}\).
It a general case that symmetrial substituted octahedral complexes are less deeper in colour than tetrahedral complexes. So \(\left[\mathrm{CoCl}_{4}\right]^{2-}\) is deep blue in colour.

Explanation:

Explanation:

\(\Delta_{0} \propto \dfrac{1}{\lambda}\)
Order of \(\Delta_{0}\) :
\({\left[ {{\text{M(en}}{{\text{)}}_{\text{3}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]^{{\text{4 - }}}}\)
Order of \(\lambda\) (wavelength of absorbed light):
\(\mathop {{{\left[ {{\text{M( en }}{{\text{)}}_{\text{3}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{green}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{orange}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]}^{{\text{4 - }}}}}\limits_{\left( {{\text{red}}} \right)} \)

Explanation:

\[\left. {\begin{array}{*{20}{l}}
{{\text{T}}{{\text{i}}^{{\text{4 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}} \\
{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}{\text{:3}}{{\text{d}}^{{\text{10}}}}} \\
{{\text{S}}{{\text{c}}^{{\text{3 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}}
\end{array}} \right\}{\text{ Completely filled or empty d - orbitals are colourless}}{\text{. }}\]
\(\mathrm{Cr}^{3+}: 3 \mathrm{~d}^{3}\) exhibits colour due to \(\mathrm{d}-\mathrm{d}\) transition.

Explanation:

Conceptual Questions

Explanation:

Aqueous of solution \(\mathrm{CoCl}_{2}\) contains \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) which is pinkish in colour so option (4) is incorrect.
Reduction potential of \(\mathrm{Co}^{3+} \rightarrow \mathrm{Co}^{2+}\) is high so option (2) is incorrect. \(\mathrm{Co}^{2+}\) does not oxidise easily to \(\mathrm{Co}^{3+}\).
It a general case that symmetrial substituted octahedral complexes are less deeper in colour than tetrahedral complexes. So \(\left[\mathrm{CoCl}_{4}\right]^{2-}\) is deep blue in colour.

Explanation:

Explanation:

\(\Delta_{0} \propto \dfrac{1}{\lambda}\)
Order of \(\Delta_{0}\) :
\({\left[ {{\text{M(en}}{{\text{)}}_{\text{3}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]^{{\text{2 + }}}}{\text{ > }}{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]^{{\text{4 - }}}}\)
Order of \(\lambda\) (wavelength of absorbed light):
\(\mathop {{{\left[ {{\text{M( en }}{{\text{)}}_{\text{3}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{green}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{M}}{{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)}_{\text{6}}}} \right]}^{{\text{2 + }}}}}\limits_{\left( {{\text{orange}}} \right)} {\text{ > }}\mathop {{{\left[ {{\text{MB}}{{\text{r}}_{\text{6}}}} \right]}^{{\text{4 - }}}}}\limits_{\left( {{\text{red}}} \right)} \)

Explanation:

\[\left. {\begin{array}{*{20}{l}}
{{\text{T}}{{\text{i}}^{{\text{4 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}} \\
{{\text{Z}}{{\text{n}}^{{\text{2 + }}}}{\text{:3}}{{\text{d}}^{{\text{10}}}}} \\
{{\text{S}}{{\text{c}}^{{\text{3 + }}}}{\text{:3}}{{\text{d}}^{\text{0}}}}
\end{array}} \right\}{\text{ Completely filled or empty d - orbitals are colourless}}{\text{. }}\]
\(\mathrm{Cr}^{3+}: 3 \mathrm{~d}^{3}\) exhibits colour due to \(\mathrm{d}-\mathrm{d}\) transition.

Explanation:

Conceptual Questions

Explanation:

Aqueous of solution \(\mathrm{CoCl}_{2}\) contains \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) which is pinkish in colour so option (4) is incorrect.
Reduction potential of \(\mathrm{Co}^{3+} \rightarrow \mathrm{Co}^{2+}\) is high so option (2) is incorrect. \(\mathrm{Co}^{2+}\) does not oxidise easily to \(\mathrm{Co}^{3+}\).
It a general case that symmetrial substituted octahedral complexes are less deeper in colour than tetrahedral complexes. So \(\left[\mathrm{CoCl}_{4}\right]^{2-}\) is deep blue in colour.