Advertisements
Advertisements
प्रश्न
Account for the following:
Cu+2 salts are coloured, while Zn2+ salts are white.
Zn2+ salts are white while Cu2+ salts are coloured. Why ?
उत्तर १
Zn2+ salts have a completely filled set of d-orbitals (3d10), while Cu2+ has an incompletely filled set of d-orbitals (3d9), and therefore, d–d transition is possible in Cu2+, leading to blue colour.
उत्तर २
| Element/Ion | Electronic Configuration |
| Zn | 3d10 4s2 |
| Zn2+ | 3d10 |
| Cu | 3d10 4s1 |
| Cu2+ | 3d9 |
The colours of salts of transition metals are due to the d-d transition that depend on the presence of incompletely filled d-orbitals. Zn2+ has completely filled d-orbitals (3d10), while Cu2+ has incompletely filled d-orbitals (3d9); therefore, d-d transition is possible in Cu2+, which imparts colour to copper(II) salts.
APPEARS IN
संबंधित प्रश्न
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
An analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.
Why does the density of transition elements increase from Titanium to Copper? (at. no. Ti = 22,
Cu = 29)
The transition metals show _________ character because of the presence of unpaired· electrons and Cu+ is ____________ because of its electronic configuration is [Ar]3d10
Which of the following statements is not correct?
Assertion: \[\ce{Cu}\] cannot liberate hydrogen from acids.
Reason: Because it has positive electrode potential.
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
Answer the following question:
Which element of the first transition series has highest third ionisation enthalpy?
A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C) with conc. \[\ce{H2SO4}\] and \[\ce{NaCl}\], chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds A to D and also explain the reactions involved.
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
