Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • (a) Account for the following :  (i) Copper (I) compounds are white whereas Copper (II) compounds are coloured. (ii) Chromates change their colour when kept in an acidic solution. (iii) Zn, Cd, Hg are considered as d-

(a) Account for the following : 

(i) Copper (I) compounds are white whereas Copper (II) compounds are coloured.

(ii) Chromates change their colour when kept in an acidic solution.

(iii) Zn, Cd, Hg are considered as d-block elements but not as transition elements.

(b) Calculate the spin-only moment of Co^{2+} (Z = 27) by writing the electronic configuration of Co and Co^{2+}.

 

 
 
 
 
 

Answers (1)

(a)

(i) Copper (I) compounds are white whereas Copper (II) compounds are coloured because, in Cu+1(3d10) there is absence of unpaired electrons while in Cu+2 (3d9 ) compounds are coloured due to unpaired e- shows d-d transition.

(ii) chromate (CrO42- ) changes to dichromate (Cr2O72- ) ion in acidic medium, hence color is changed. 

(iii) Due to completely filled d-orbitals in their ground state as well as in oxidized state,  Zn, Cd, Hg are considered as d-block elements but not as transition elements.

(b) Co = [Ar]4s2 3d7 , Co^{2+} =[Ar] 3d7

\mu = \sqrt{n(n+2)} = \sqrt{3(3+2)} = \sqrt{15}

= 3.2 BM 

Posted by

Safeer PP

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE Class 12 board exams 2025 to have 50% competency-based questions; no change in 10th
anam-khan

CBSE Class 12 board exams 2024 over; expected result date, trends of last 10 years
anam-khan

CBSE Class 12 accountancy board exam analysis 2024 out; paper rated easy, balanced

Latest Question