Chemistry - Complete d-block Question with Solution | TestHub

In${\mathrm{C}\mathrm{u}\mathrm{F}}_2$,${\mathrm{C}\mathrm{u}}^{2+}$ion exist, having$d^9$configuration. Unpaired electron causes colour ($d-d$transition). In the crystalline form,${\mathrm{C}\mathrm{u}\mathrm{F}}_2$is blue coloured.

While in other compounds$\text{Cu}$is in positive one oxidation state and does not have unpaired electron. Hence all are colourless.