Colours in Coordination Compounds

Q. Which of the following is coloured tetrahedral complex species?

1. $\left[Cu\right(PP{h}_3{)}_4{]}^{+}$
2. $\left[Zn\right(H_{2}O{)}_6{]}^{2+}$
3. $\left[Cu\right(N{H}_3{)}_4]S{O}_4$
4. $Mn{O}_4^{-}$

Q. Aqueous $CuS{O}_4$ changes its colour from sky blue to deep blue on the addition of $N{H}_3$ because:

1. $C{u}^{2+}$ forms a hydrate
2. $\left[Cu\right(H_{2}O{)}_4{]}^{2+}$ is a labile complex and changes to $\left[Cu\right(N{H}_3{)}_4{]}^{2+}$ as $N{H}_3$ is a stronger ligand than $H_{2}O$
3. $C{u}^{2+}$ changes to $C{u}^{+}$
4. All of the above

Q. The correct order of wavelengths of absorption is:

1. $\left[Ni\right(N{O}_2{)}_6{]}^{4-}<\left[Ni\right(N{H}_3{)}_6{]}^{2+}<\left[Ni\right(H_{2}O{)}_6{]}^{2+}$
2. $\left[Ni\right(N{O}_2{)}_6{]}^{4-}<\left[Ni\right(H_{2}O{)}_6{]}^{2+}<\left[Ni\right(N{H}_3{)}_6{]}^{2+}$
3. $\left[Ni\right(H_{2}O{)}_6{]}^{2+}<\left[Ni\right(N{H}_3{)}_6{]}^{2+}<\left[Ni\right(N{O}_2{)}_6{]}^{4-}$
4. $\left[Ni\right(N{H}_3{)}_6{]}^{2+}<\left[Ni\right(H_{2}O{)}_6{]}^{2+}<\left[Ni\right(N{O}_2{)}_6{]}^{4-}$

Q. Which of the following complex ions is not expected to absorb visible light ?

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1. $\left[Cr\right(N{H}_3{)}_6{]}^{3+}$
2. $\left[Ni\right(CN{)}_4{]}^{2-}$
3. $\left[Fe\right(H_{2}O{)}_6{]}^{2+}$
4. $\left[Ni\right(H_{2}O{)}_6{]}^{2+}$

Q. A compound absorbing violet colour from sunlight will be

1. yellow
2. Green
3. orange
4. violet

Q. $CuS{O}_4.5H_{2}O$ is blue is colour while anhydrous $CuS{O}_4$ is colourless due to:

1. anhydrous $CuS{O}_4$ undergoes d-d transition due to crystal field splitting
2. Due to absence of water(ligand), d-d transitions is not possible in $CuS{O}_4$
3. Presence of strong field ligand in $CuS{O}_4.5H_{2}O$
4. colour is lost due to unpaired electrons

Q. When $FeC{l}_3$ is treated with $K_4\left[Fe\right(CN{)}_6]$, a blue coloured compound is formed. What are the total number of atoms per formula molecule? (supposing no K is present in blue coloured compound)

Q. Formation of Prussian blue coloured precipitate during detection of nitrogen in an organic compound indicate the presence of which of the following compound?

1. $F{e}_4\left[Fe\right(CN{)}_6{]}_3$
2. $F{e}_3\left[Fe\right(CN{)}_6{]}_2$
3. $F{e}_2\left[Fe\right(CN{)}_6]$
4. None of the above

Q.

The intense blue colour of Prussian blue salts arises from:

1. d – d transition

2. inner valence electron transfer

3. ligand to metal charge transfer

4. metal to ligand charge transfer