Factors Affecting CFSE and Conclusions

Q. The CFSE for octahedral $[CoC{l}_6{]}^{4-}$ is $18,000c{m}^{–1}$.
The CFSE for tetrahedral $[CoC{l}_4{]}^{2-}$ will be

1. $18,000c{m}^{–1}$
2. $16,000c{m}^{–1}$
3. $8,000c{m}^{–1}$
4. $20,000c{m}^{–1}$

Q. The factors that affect the crystal field splitting is

1. coordination number
2. oxidation state
3. ligand field strength
4. all of the above

Q. Sort the following complexes according to their crystal field stabilization energy (CFSE)

1. $\left[Fe\right(CN{)}_6{]}^{3-}$
2. $[{\mathrm{CoCl}}_6{]}^{4-}$
3. $\left[\mathrm{Co}\right(\mathrm{CN}{)}_6{]}^{3-}$
4. ${\left[Fe\right(H_{2}O{)}_6]}^{3+}$

Q. The complex ion that has the minimum wavelength of absorption in the visible region is:

1. ${\left[Co\right(N{H}_3{)}_6]}^{3+}$
2. ${\left[CoCl\right(N{H}_3{)}_5]}^{2+}$
3. $\text{cis}-{\left[CoC{l}_2\right(N{H}_3{)}_4]}^{+}$
4. $\text{trans}-{\left[CoC{l}_2\right(N{H}_3{)}_4]}^{+}$

Q. For $M{n}^{3+}$, pairing energy is 28000 $c{m}^{-1}$. ${\Delta }_{o}for\left[Mn\right(CN{)}_6{]}^{3-}is38500c{m}^{-1}$. Which of the following is incorrect?

1. Complex will be coloured
2. Complex will be a low spin complex
3. Net CFSE = -33600 $c{m}^{-1}$
4. Complex will be colourless

Q.

The d - electron configurations of $M{n}^{2+},F{e}^{2+},C{o}^{3+},andN{i}^{2+}are3d^5,3d^6,3d^6,3d^8,$ respectively. Which of the following aqua complexes will exhibit the minimum paramagnetic behavior?

1. $\left[Fe\right(H_{2}O{)}_6{]}^{2+}$

2. $\left[Co\right(H_{2}O{)}_6{]}^{3+}$

3. $\left[Ni\right(H_{2}O{)}_6{]}^{2+}$

4. $\left[Mn\right(H_{2}O{)}_6{]}^{2+}$

Q. Which of the following ligands causes maximum crystal field splitting?

1. $SC{N}^{-}$
2. $en$
3. $C_2{O}_4{}^{2-}$
4. $N{H}_3$

Q. The complex ion that has the minimum wavelength of absorption in the visible region is:

1. ${\left[Co\right(N{H}_3{)}_6]}^{3+}$
2. ${\left[CoCl\right(N{H}_3{)}_5]}^{2+}$
3. $\text{cis}-{\left[CoC{l}_2\right(N{H}_3{)}_4]}^{+}$
4. $\text{trans}-{\left[CoC{l}_2\right(N{H}_3{)}_4]}^{+}$

Q. $\left[Ti\right(NCS{)}_6{]}^{3-}$ ion exhibits a single absorption band at 544 nm. What will be the crystal field splitting energy (in kJ/mol) of the complex ?$(h=6.626\times {10}^{-34}Js;c=3\times {10}^{8}m/s;N_A=6.02\times {10}^{23}ions/mole)$

1. $240kJ/mol$
2. $220kJ/mol$
3. $270kJ/mol$
4. $250kJ/mol$

Q. The $\left[Ti\right(NCS{)}_6{]}^{3-}$ ion exhibits a single absoption band at $544nm$. What will be the crystal field splitting energy of the complex? $(\text{Planck constant}=6.626\times {10}^{-34}Js)$

1. $2.65\times {10}^{18}J$
2. $12.5\times {10}^{-19}J$
3. $2.65\times {10}^{-18}J$
4. $3.65\times {10}^{-19}J$

Q. $\left[Ti\right(H_{2}O{)}_6{]}^{3+}$ absorbs light of wavelength 498 nm during a d–d transition. The octahedral splitting energy for the above complex is $\times {10}^{-19}J$. (Round off to the nearest integer). $h=6.626\times {10}^{-34}\text{J s}$; c = 3 \times 10^8~\text{ m s}^{-1}\).

Q. Which one of the following complexes is violet in colour ?

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> JEE Main 2021

1. $\left[Fe\right(CN{)}_{5}NOS{]}^{4-}$
2. $\left[Fe\right(CN{)}_6{]}^{4-}$
3. $F{e}_4\left[Fe\right(CN{)}_6{]}_3.H_{2}O$
4. $\left[Fe\right(SCN{)}_6{]}^{4-}$

Q. Sort the following complexes according to their crystal field stabilization energy (CFSE)

1. $\left[Fe\right(CN{)}_6{]}^{3-}$
2. $[{\mathrm{CoCl}}_6{]}^{4-}$
3. $\left[\mathrm{Co}\right(\mathrm{CN}{)}_6{]}^{3-}$
4. ${\left[Fe\right(H_{2}O{)}_6]}^{3+}$