Given below are two statements: In the light of the above statements, choose the correct answer from the options given below
- Statement I is true but Statement II is false
- Both Statement I and Statement II are false
- Statement I is false but Statement II is true
- Both Statement I and Statement II are true
Answer
(4) Both Statement I and Statement II are true
Solution
Statement I: the nitrite ion (NO2-) is confirmed by the Griess-Ilosvay test, in which the acidified solution is treated with sulphanilic acid and α-naphthylamine. True.
Statement II: in acidic medium, NO2- gives nitrous acid, which diazotises sulphanilic acid:
HO3S-C6H4-NH2 + HNO2 + H+ HO3S-C6H4-N2+ + 2H2O
The diazonium ion then couples with α-naphthylamine (at its para position) to form a red azo dye. True.
Both statements are true, and Statement II correctly describes the chemistry of the test in Statement I.
Answer: (4)