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← JEE Main 2021 · 24 Feb · Shift 1
ChemistrySingle correct+4 / -1Question 50 of 90

JEE Main 2021 · 24 Feb · Shift 1, Chemistry question 50

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.

Choose one option
Answer and worked solution

Official answer: B

Borax bead. Cupric metaborate is blue, not colourless, so I is false. Heating with CuSO₄ in the non-luminous (oxidising) flame gives cupric metaborate; the cuprous salt forms in the luminous (reducing) flame, so II is false too.

(B)