HYDROCARBONS QUIZ-12

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Hydro Carbons Quiz-12

Dear Readers,

The one subject in NEET which is candidates who can easily attain good marks is Chemistry. That's the reason, often, one doesn’t pay notice and choose to compromise it. But if one wants to rank above others, the tip is to be thorough with NEET chemistry concepts. The understanding of reactions and definite basic understanding is what requires major attention in Chemistry but once done it only gets simpler from there. The main focus on the to-do list should be on getting a hang of the NCERT syllabus of NEET chemistry..

Q1. An alkene having molecular formula C₉H₁₈ on ozonolysis gives 2, 2-dimethyl propanal and 2-butanone. The alkene is

•  2,2,2-trimethyl-3-hexene
•  2,2,6-trimethyl-3-hexane
•  2,3,4-trimethyl-2-hexene
•  2,2,4-trimethyl-3-hexene

Solution
(d).

To determine alkene, place these products with O-atoms face to face and replace O-atoms by = bond.

Q2.When acetylene is passed through dil. H₂SO₄ in presence of HgSO₄, the compound formed is

•  Ether
•  Acetaldehyde
•  Acetic acid
•  Ketone

Solution
(b).

Q3.  

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Solution
(a).

Q4. 1,1,2,2-tetrabromoethane on heating with Zn powder in alcohol finally gives:

•  Methane
•  Ethane
•  Ethyne
•  Ethene

Solution
(c).

Q5. Propane cannot be prepared from which reaction?

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•  None of the above

Solution
 (a).

Hydroboration of alkenes followed by hydrolysis in basic medium yield alcohol.

Reduction of alkyl halides yield alkane.

Decarboxylation of sodium salt of fatty acid yield alkane having one carbon atom less than parent acid salt.

Q6. Which of the following species is aromatic?

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Solution
(b).A compound is said to be aromatic if it meets of the following criteria.
1.The rings of the compound should be planer.
2.The cyclic system must contain (4π+2)π-electrons.
Only option (b) contains 6π-electron, so it is aromatic.

Q7. Both methane and ethane may be obtained by a suitable one-step reaction from

•  CH₃I
•  C₂H₅I
•  CH₃OH
•  C₂H₂OH

Solution
(a)

Q8. The product B is:

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Solution
(c)

Q9.A hydrocarbon of molecular formula C₆H₁₀ reacts with sodamide and the same on ozonolysis followed by hydrogen peroxide oxidation gives two molecules of carboxylic acids, one being optically active. Then, the hydrocarbon may be

•  1-hexyne
•  3-hexyne
•  3-methyl-1-pentyne
•  3,3-dimethyl-1-butyne

Solution
(c).

Q10. The reduction of an alkyne to alkene using lithium metal in liquid ammonia as solvent results into

•  cis addition of hydrogen atoms
•  trans addition of hydrogen atoms
•  Both cis and trans additions of hydrogen atoms. The relative amounts of the two depends on temperature
• Both cis and trans additions of hydrogen atoms. The relative amounts depend on the nature of alkyne

Solution
(b) For transproduct we take Na/liquid NH₃ or Li-NH₃/C₂H₅OH or LiAlH₄ as a reducing agent (anti-addition)