Hydrocarbons MCQ Questions and Answers Pdf :
Practicing these MCQ on Hydrocarbons for NEET will help you to answer every question that is being asked in the board exams as well as in NEET Exam also. Students can solve these Hydrocarbons MCQ for NEET Pdf Download to know their preparation level. Hydrocarbons Objective type Questions help the students to understand the concepts thoroughly and to score good marks in NEET. The below Multiple Choice Questions on Hydrocarbons with answers Pdf have been prepared as per the latest syllabus. Practice it now and score high in NEET exam.
MCQ on Hydrocarbons for NEET :
1. The order of reactivity of alkyl halides in Wurtz reaction is__________
(1) R–I > R–Br > R–Cl
(2) R–I < R–Br < R–Cl
(3) R–Br > R–I < R–Cl
(4) R–I > R–Cl > R–Br
Answer: 1
2. Reduction of aldehydes and ketones into hydrocarbons using zinc amalgam and conc. HCl is called_____
(1) Cope reduction
(2) Dow reduction
(3) Wolf-kishner reduction
(4) Clemmensen reduction
Answer: 4
3. Which of the compounds with molecular formula C5H10 yields acetone on ozonolysis_________
(1) 3-Methyl-1-butene
(2) Cyclopentene
(3) 2-Methyl-1-butene
(4) 2-Methyl-2-butene
Answer: 4
4. Kolbe’s electrolysis of a mixture of pot. Propanoate and pot. 3-Methylbutanoate gives______
(1) Butane and isobutane
(2) Butane and 2,5–dimethylhexane
(3) Butane, 2,5-dimethylhexane and isohexane
(4) Butane and isohexane
Answer: 3
5. The Corey-House alkane synthesis is carried out by treating an alkyl halide with________
(1) Lithium metal
(2) Copper metal
(3) Lithium metal followed by reaction with cuprous iodide and then treating the product with an alkyl halide
(4) Cuprous iodide followed by reaction with alkyl halide
Answer: 3
6. Which of the following acids on decarboxylation gives isobutane________
(1) 2,2–Dimethyl butanoic acid
(2) 2,2–dimethyl propanoic acid
(3) 3–Methyl pentanoic acid
(4) 2–Methyl butanoic acid
Answer: 2
7. Which of the following compound is not suitable to obtain from wurtz reaction ?
(1) ethane
(2) butane
(3) isobutane
(4) hexane
Answer: 3
8. When ethyl chloride and n-propyl chloride undergoes wurtz reaction which is not obtained________
(1) n-butane
(2) n-pentane
(3) n-hexane
(4) isobutane
Answer: 4
9. Kolbe’s electrolysis of sodium maleate at anode gives__________
(1) Only acetylene
(2) Only CO2
(3) Acetylene + CO2
(4) CO2 + H2
Answer: 3
10. The pH of solution in Kolbe’s electrolysis___________
(1) increase with time
(2) decrease with time
(3 remains constant
(4) nothing can be said
Answer: 1
11. Which of the following compound will not give a precipitate with Tollen’s reagent_____
(1) ethyne
(2) 1-butyne
(3) 3-methyl -1-butyne
(4) 1-pentene
Answer: 4
12. Liquid hydrocarbons can be converted to a mixture of gasesous hydrocarbons by______
(1) Hydrolysis
(2) Oxidation
(3) Cracking
(4) Distillation under reduced pressure
Answer: 3
13. Benzene is________
(1) Weakly attracted in the magnetic field
(2) Strongly attracted in the magnetic field
(3) Strongly repelled in magnetic field
(4) Weakly repelled in magnetic field
Answer: 4
14. The oxidation of benzene by V²O⁵ in the presence of air produces________
(1) benzoic acid
(2) benzaldehyde
(3) benzoic anhydride
(4) maleic anhydrid
Answer: 4
15. Ozonolysis of 3–Methyl–1–butene gives a mixture of_____
(1) Propanal and ethanal
(2) Propanone and ethanal
(3) 2–Methylpropanal and methanal
(4) Butanone and methanal
Answer: 3
16. Which alkene gives acetone only on ozonolysis______
(1) Isobutylene
(2) 2,3–Dimethyl–1–butene
(3) 2,3–Dimethyl–2–butene
(4) 3,3–Dimethyl–1–butene
Answer: 3
17. Oxidation of isobutylene with acid potassium permanganate gives________
(1) Acetone + CO2
(2) Acetic acid
(3) Acetic acid + CO2
(4) Acetic acid + acetone
Answer: 1
18. Which of the following reactions is used for locating the position of double bond in an alkene_________
(1) Hydroboration
(2) Hydroxylation
(3) Chlorohydroxylation
(4) Ozonolysis
Answer: 4
19. Which one of the following has the smallest heat of hydrogenation per mole_____________
(1) 1–butene
(2) Trans–2–butene
(3) Cis–2–butene
(4) Propene
Answer: 2
20. The volume of methane evolved by treatement of 16.6 g of methyl magnesium iodide with water at S.T.P. is________
(1) 224 mL
(2) 2.24 L
(3) 0.224 L
(4) 22.4 L
Answer: 2
21. The molecules having dipole moment are________
(1) 2,2-dimethylpropane
(2) trans pent-2-ene
(3) cis-hex-3-ene
(4) 2 and 3
Answer: 4
22. The highest boiling point is expected for__________
(1) Isooctane
(2) 2,2,3,3-tetramethylbutane
(3) n-octane
(4) n-butane
Answer: 3
23. Pyrolysis of alkanes is a____________
(1) Nucleophilic addition reaction
(2) Free radical substitution reaction
(3) Electrophilic addition reaction
(4) Free radical elimination reaction
Answer : 4
24. Which of the following does not give alkane with R—Mg—X.
(1) Ph—OH
(2) C⁶H⁶
(3) CH³COOH
(4) HCl
Answer: 2
25. Which of the following reaction can not be used to obtained propane in good yield________
(1) Wurtz reaction
(2) Corey-house reaction
(3) Decarboxylation of acid salt
(4) All of them
Answer: 1
26. The compound with the highest boiling point is_________
(1) n-hexane
(2) n-pentane
(3) 2,2-dimethyl propane
(4) propane
Answer: 1
27. Photochemical chlorination of alkane is initiated by a process of_________
(1) pyrolysis
(2) substitution
(3) Homolysis
(4) Peroxidation
Answer: 3
28. Isomerization in alkane may be brought about by using_______
(1) Al²O³
(2) Fe²O³
(3) AlCl³ and HCl
(4) Concentrated H²SO⁴
Answer: 3
29. Bromination of an alkane as compared to chlorination proceeds___________
(1) At a slower rate
(2) At a faster rate
(3) With equal rates
(4) With equal or different rate depends upon the temperature
Answer: 1
30. An alkene on treating with hot acidified KMnO4 gives 4 – oxopentanoic acid. The alkene is_________
(1) Pentene
(2) 2–Pentene
(3) 1–Methyl cyclobutene
(4) 1, 2– Dimethyl cyclopropene
Answer: 3
31. The addition of Br2 to cis–2–butene produces____________
(1) (+) –2, 3–dibromobutane only
(2) (–) –2, 3–dibromobutane only
(3) racemic –2, 3–dibromobutane
(4) meso –2, 3–dibromobutane
Answer: 3
32. Which of the following reactions does not involve a C—C bond formation_________
(1) Hydrolysis of a Grignard reagent
(2) Combination of two alkyl free radicals
(3) Corey-House synthesis of alkanes
(4) RNa + R–Br ———> R–R + NaBr
Answer: 1
33. If two moles of Isopropyl chloride reacts with Na in presence of dry ether. Which alkane is obtained__________
(1) Hexane
(2) 2, 3-Dimethyl butane
(3) Isopentane
(4) Neopentane
Answer: 2
34. If isopropyl chloride and ethyl chloride both react with Na in presence of dry ether which alkanes are obtained__________
(1) n-Butane
(2) 2-Methyl butane
(3) 2, 3-Dimethyl butane
(4) All of them
Answer: 4
35. Which of the following compound can not be obtained from single alkyl halide by wurtz reaction________
(1) ethane
(2) butane
(3) isobutane
(4) hexane
Answer: 3
36. How many acids can be taken to obtain isobutane by decarboxylation ?
(1) 4
(2) 3
(3) 2
(4) 5
Answer: 3
37. When ethene reacts with bromine in aqueous sodium chloride Solution. The product(s) obtained is (are)___________
(1) Ethylene dibromide only
(2) Ethylene dibromide and 1–bromo–2–chloro ethane
(3) 1–bromo–2–chloroethane only
(4) Ethylene dichloride only
Answer: 2
38. A compound having a bond angle 180° is__________
(a) alkyne
(b) alkane
(c) alkene
(d) cycloalkane
Answer: 1
39. Which one of these is not true for benzene?
(1) There are three carbon-carbon single bonds and three carbon-carbon double bonds.
(2) Heat of hydrogenation of benzene is less than the theoretical value
(3) It forms only one type of mono substituted product
(4) The bond angle between carbon-carbon bonds is 120 Degree
Answer : 1
40. Presence of a nitro group in a benzene ring____________
(1) Activates the ring towards electrophilic substitution
(2) Renders the ring basic
(3) Deactivates the ring towards nucleophilic substitution
(4) Deactivates the ring towards electrophilic substitution
Answer : 4