JEE PYQ: P Block Elements Question 12
Question 12 - 2021 (24 Feb Shift 1)
Given below are two statements:
Statement I: Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame.
Statement II: Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame. In the light of the above statements, choose the most appropriate answer from the options given below.
(1) Statement I is false but statement II is true.
(2) Statement I is true but Statement II is false.
(3) Both Statement I and Statement II are true.
(4) Both Statement I and Statement II are false.
Show Answer
Answer: (4)
Solution
Both are False. (1) Copper sulphate forms copper meta borate with boric anhydride: $\text{CuSO}_4 \to \text{CuO} + \text{SO}_3$. $\text{CuO} + \text{B}_2\text{O}_3 \to \text{Cu(BO}_2\text{)}_2$ (blue in cold oxidising flame, non-luminous flame). (2) Blue coloured metal borate is reduced to copper in a luminous flame.
BETA
