+91-8076753736 support@wiredfaculty.com
logo
logo

Sponsor Area

The D-And-f-Block Elements

Question
CBSEENCH12007175
Wired Faculty App

A green chromium compound (A) on fusion with alkali gives a yellow compound (B) which on acidification gives an orange coloured compound (C). ‘C’ on treatment with NH4Cl gives an orange coloured product (D), which on heating decomposes to give back (A). Identify A, B, C and D. Write equations for reactions.

Solution
(a)

(i) The ionisation energy gradually increases with increase in atomic number along a given transition series. So transition elements tend to be unreactive with increase in atomic number in a series.

(ii) In transition elements, the energies of (n – 1) d-orbitals and ns orbitals are very close. Hence electrons from both can participate in bonding. The principal oxidation state of lanthanoids is +3.




The equation for reactions are as follows:

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

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?

Why the melting points of transition elements are high?

Why Zn, Cd and Hg are not regarded as transition elements?

Name the first element of 3rd transition series.

Though copper, silver and gold have completely filled sets of d-orbitals yet they are considered as transition metals. Why?

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation