Colour of Lanthanides

Q. The lanthanide that would show colour is:

1. $G{d}^{3+}$
2. $L{a}^{3+}$
3. $L{u}^{3+}$
4. $S{m}^{3+}$

Q. Identify the correct pair of colorless species-

1. $Co{F}_6^{3-}$ and $NiC{l}_4^{2-}$
2. $Ti{F}_6^{2-}$ and $Co{F}_6^{3-}$
3. $Ti{F}_6^{2-}$ and $C{u}_{2}C{l}_2$
4. $C{u}_{2}C{l}_2$ and $NiC{l}_4^{2-}$

Q. Identify the correct pair of colorless species-

1. $Co{F}_6^{3-}$ and $NiC{l}_4^{2-}$
2. $Ti{F}_6^{2-}$ and $Co{F}_6^{3-}$
3. $Ti{F}_6^{2-}$ and $C{u}_{2}C{l}_2$
4. $C{u}_{2}C{l}_2$ and $NiC{l}_4^{2-}$

Q. Generally transition elements and their salts are colored due to the presence of unpaired electrons in metal ions. Which of the following compounds are colored?

1. $KMn{O}_4$
2. $Ce(S{O}_4{)}_2$
3. $TiC{l}_4$
4. $C{u}_{2}C{l}_2$