Question
Chemistry Question on d -and f -Block Elements
Which of the following compound, on reaction with NaOH and Na2O2, gives yellow colour?
A
Zn(OH)2
B
Al(OH)3
C
Cr(OH)3
D
CaCO3
Answer
Cr(OH)3
Explanation
Solution
Yellow colour is due to the formation of CrO42− ion. Cr(OH)3+NaOH+Na2O2→Na2CrO4+2H2O