Detection of Elements in Organic Compounds
Learn qualitative tests for detecting elements like nitrogen, sulfur, and halogens in organic compounds, especially Lassaigne's test and its variations.
Why this shows up in the exam
NEET/JEE often test your knowledge of these classic detection methods and their underlying chemistry.
How NEET tests this
Practise it
These are real questions from past NEET papers that test this exact idea.
The Lassaigne's extract is boiled with conc. HNO₃ while testing for halogens. By doing so it
Push further
More challenging5 harder questions built from the past papers above — a step up in difficulty, with distractors designed so you can't get there by elimination. Written and checked by our reviewers, not from a real paper.
A student performs Lassaigne's test on an organic compound. After preparing the sodium fusion extract, they add freshly prepared ferrous sulfate solution and then acidify with concentrated sulfuric acid. A Prussian blue coloration is observed. This indicates the presence of which element(s)?
More from Organic Chemistry - Some Basic Principles and Techniques
IUPAC Nomenclature of Organic Compounds
Learn the systematic rules for naming organic compounds, including those with multiple substituents, functional groups, unsaturations, and special cases like branched chains and aromatic compounds.
Structure and Bonding in Organic Molecules
Understand the types of covalent bonds (sigma and pi), hybridization states, bond angles, and how these relate to molecular structure in organic compounds.
Isomerism in Organic Chemistry
Explore the different types of isomerism, including structural isomerism (chain, position, functional, metamerism, tautomerism) and stereoisomerism (geometric and optical isomers).
Reactive Intermediates: Carbocations, Carbanions, and Free Radicals
Learn about the structure, stability, and formation of carbocations, carbanions, and free radicals in organic reactions.
Purification Techniques in Organic Chemistry
Familiarize yourself with methods like sublimation, distillation (including steam distillation), chromatography, and criteria for selecting appropriate purification techniques.
Quantitative Estimation of Elements
Understand methods for quantitative estimation of carbon, hydrogen, and nitrogen (Dumas and Kjeldahl methods), including calculations and limitations.