Given below are two statement :
Statement (I) : Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test.
Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test.
In the light of the above statements, choose the correct answer from the options given below :
Statement (I) : Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test.
Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test.
In the light of the above statements, choose the correct answer from the options given below :
- (A)Both Statement I and Statement II are true
- (B)Both Statement I and Statement II are false
- (C)Statement I is true but Statement II is false✓ Correct
- (D)Statement I is false but Statement II is true
Answer: (C)
Solution
Lassaigne's test detects nitrogen, sulphur, halogens, and phosphorus in an organic compound, so Statement I is correct.
The test works by fusing the organic compound with molten sodium metal, not magnesium: this fusion converts the covalently bound N, S, halogen, and P atoms into ionic sodium salts — , , sodium halides, and — which are then detected by standard qualitative tests (Prussian blue for cyanide, lead acetate/lead sulphide for sulphide, silver nitrate for halide, and so on). Since sodium, not magnesium, performs this fusion, Statement II is false.
Statement I is true, but Statement II is false.
The test works by fusing the organic compound with molten sodium metal, not magnesium: this fusion converts the covalently bound N, S, halogen, and P atoms into ionic sodium salts — , , sodium halides, and — which are then detected by standard qualitative tests (Prussian blue for cyanide, lead acetate/lead sulphide for sulphide, silver nitrate for halide, and so on). Since sodium, not magnesium, performs this fusion, Statement II is false.
Statement I is true, but Statement II is false.
JEE Main · 2025 · 22 Jan 2025 · Shift 2 · Single correct option