☰
✕

The d-And-f-Block Elements
Question
Wired Faculty App

Cu+ is colourless but Cu2+ is coloured. Why?

Answer

Transition element exhibit colour due to d-d transition. d-d transition is possible only when d subshell have unpaired electron. Cu+ has completely filled orbital: [Noble gas] 3d10, where as Cu2+ has partially filled orbital : [Noble gas]3d9. Hence Cu+ is colourless but Cu2+ is coloured.

Sponsor Area

Some More Questions From The d-And-f-Block Elements Chapter

In the series Sc (Z = 21) to Zn(Z = 30), the enthalpy of atomisation of zinc is the lowest i.e., 26, kJ mol. Why?

The E° (M2+/M) value for copper is positive (+ 0.34 V). What is possibility the reason for this? 

How would you account for the irregular variation of ionisation enthalpies (first and second) in the first series of the transition elements?

Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?

Which is a stronger reducing agent Cr2+ or Fe2+ and why?

Explain why Cu+ ion is not stable in aqueous solutions?

Actinoid contraction is greater from element to element than lanthanoid contraction. Why?

On what ground can you say that scandium (Z = 21) is a transition element but zinc (Z = 30) is not?

The outer electronic configuration of copper is 3d10 4s1, yet it is considered transition element. Why?