Unit 20: Principles Related to Practical Chemistry — Online MCQ Test
CHEMISTRY · NEET (All) · NEET
Practice Unit 20: Principles Related to Practical Chemistry with a free chapter-wise online MCQ test.
This chapter covers: Detection of extra elements (Nitrogen Sulphur halogens) in organic compounds; Detection of the following functional groups; hydroxyl (alcoholic and phenolic) carbonyl (aldehyde and....
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Unit 20: Principles Related to Practical Chemistry — Important Questions & Answers
Which one of the following reactions does NOT belong to “Lassaigne’s test”?
- A. Na + C + N -> NaCN
- B. 2Na + S -> Na2S
- C. Na + X -> NaX
- D. 2CuO + C -> 2Cu + CO2
Answer: D. 2CuO + C -> 2Cu + CO2
Options 1, 2, and 3 are standard fusion reactions in Lassaigne's test. Option 4 is not part of the standard sodium fusion procedure.
Options 1, 2, and 3 are standard fusion reactions in Lassaigne's test. Option 4 is not part of the standard sodium fusion procedure.
Which of the following is an analgesic?
- A. Penicillin
- B. Streptomycin
- C. Chloromycetin
- D. Novalgin
Answer: D. Novalgin
Novalgin (Metamizole) is a well-known analgesic (painkiller) and antipyretic. Penicillin, Streptomycin, and Chloromycetin are antibiotics.
Novalgin (Metamizole) is a well-known analgesic (painkiller) and antipyretic. Penicillin, Streptomycin, and Chloromycetin are antibiotics.
Fehling’s solution ‘A’ is
- A. alkaline solution of sodium potassium tartrate (Rochelle’s salt)
- B. aqueous sodium citrate
- C. aqueous copper sulphate
- D. alkaline copper sulphate
Answer: C. aqueous copper sulphate
Fehling’s solution A is aqueous copper sulphate; Fehling’s solution B is alkaline sodium potassium tartrate.
Fehling’s solution A is aqueous copper sulphate; Fehling’s solution B is alkaline sodium potassium tartrate.
On heating some solid substance change from solid to vapour state without passing through liquid state. The technique used for the purification of such solid substances based on the above principle is known as:
- A. Distillation
- B. Chromatography
- C. Crystallization
- D. Sublimation
Answer: D. Sublimation
The direct change from solid to vapour without passing through liquid is sublimation, and the purification technique based on it is also called sublimation.
The direct change from solid to vapour without passing through liquid is sublimation, and the purification technique based on it is also called sublimation.
During the preparation of Mohr’s salt solution (ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of Fe2+ ion?
- A. dilute nitric acid
- B. dilute sulphuric acid
- C. dilute hydrochloric acid
- D. concentrated sulphuric acid
Answer: B. dilute sulphuric acid
Dilute sulphuric acid is added because it maintains acidic medium and does not interfere with Fe2+ ions.
Dilute sulphuric acid is added because it maintains acidic medium and does not interfere with Fe2+ ions.