NEETChemistryGeneral Organic Chemistry
Three students, Manish, Ramesh and Rajni were determining the extra elements present in an organic compound given by their teacher. They prepared the Lassaigne’s extract (L.E.) independently by the fusion of the compound with sodium metal. Then they added solid FeSO 4 and dilute sulphuric acid to a part of Lassaigne’s extract. Manish and Rajni obtained prussian blue colour but Ramesh got red colour. Ramesh repeated t
Options
- AIn Lassaigne’s test SCN – ions are formed due to the presence of sulphur and nitrogen both. These give red col
- BIn Lassaigne’s test Na + ions are formed due to the presence of sulphur and nitrogen both. These give red colo
- CIn Lassaigne’s test Fe 2+ ions are formed due to the presence of sulphur and nitrogen both. These give red col
- DIn Lassaigne’s test CN – ions are formed due to the presence of sulphur and nitrogen both. These give red colo
Correct answer
A. In Lassaigne’s test SCN – ions are formed due to the presence of sulphur and nitrogen both. These give red col
Step-by-step solution
Correct Option is : (A) In Lassaigne’s test SCN – ions are formed due to the presence of sulphur and nitrogen both. These give red colour with Fe 3+ ions. This happens when fusion is not carried out in the excess of sodium.