hydrocarbons-quiz-4

Hydrocarbons Quiz-4

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. Methyl bromide is converted into ethane by heating it in ether medium with

•  Al
•  Zn
•  Na
•  Cu

Solution


 

Q2.Alkynes occur in nature in the:

•  Free state
•  Partially free state
•  Not in the free state
•  None of the above

Solution

(c) Alkynes are not found in free state due to their high reactivity.

Q3. Alkanes containing…..carbon atoms are converted into an aromatic hydrocarbon, when heated in presence of Cr₂ O₃ on Al₂ O₃ 

•  6 to 10
•  4 to 8
•  3 to 6
•  5 to 6

Solution

Q4. 10mL of a certain hydrocarbon require 25mL of oxygen for complete combustion and the volume of CO₂ produced is 20mL. what is the formula of hydrocarbon?

•  C₂ H₂
•  C₂ H₄
•  CH₄
•  C₂ H₆

Solution
(a) C₂ H₂+5/2 O₂⟶2CO₂+H₂ O; 1 mole or 1 vol. of C₂ H₂ requires 2.5 mole or 2.5 vol. of O₂.

Q5.Nitrobenzene can be prepared from benzene by using a mixture of concentrated HNO₃ and concentrated H₂ SO₄. In the nitrating mixture, HNO₃ acts as

•  Base
•  Acid
•  Reducing agent
•  Catalyst

Solution
  (a) In the laboratory, nitrobenzene is prepared by nitration of benzene with the mixture of nitric acid and sulphuric acid at temperature below60℃. In which HNO₃ acts as a base  

Q6. 

•  C₂ H₅ I
•  CHI₃
•  CH₃ CHO
•  C₂ H₅ OH

Solution
(b) CHI₃ 

Q7.Which of the following will have least hindered rotation about carbon-carbon bond?

•  Ethane
•  Ethylene
•  Acetylene
•  Hexachloroethane

Solution

(a) Least hindered rotation means free rotation, i.e., round a single bond.

Q8.If 20cm³ of methane (CH₄) is burnt using 50cm³ of oxygen. The volume of the gases left after cooling to room temperature will be:

•  60cm³
•  70cm³
•  30cm³
•  50cm³

Solution


 

Q9.Which compound does not give precipitate with ammoniacal silver nitrate solution?

•  C₂ H₅-C≡CH
•  CH₃-C≡C-CH₃
•  
  
  
•  Ph-CH₂-C≡CH

Solution

(b) Only terminal alkynes give precipitate with ammoniacal silver nitrate solution. Among the given, CH₃-C≡CH-CH₃ is not a terminal alkyne. Thus, it does not give precipitate with ammoniacal AgNO₃.

Q10. Which of the following statements is incorrect?

•  Acetylene is explosive above 2 atm
•  It is transported by dissolving in acetone
•  It has unpleasant garlic odour
•  It is used in the manufacture of Lewisite

Solution

(c) Pure C₂ H₂ has ethereal odour.