Alkynes(Acidic Character: Addition of Hydrogen,...) NEET Questions

Organic Chemistry - Hydrocarbons

Alkynes(Acidic Character: Addition of Hydrogen,...) MCQ Questions


13.
Which one will not give a precipitate with Tollen's reagent?
A.
CH3-CH2-C≡C-CH3
B.
CH3-C≡CH
C.
CH3-CH2-C≡CH
D.
HC≡CH
😑 View Answer Rough Work Error
ANSWER :
A. CH3-CH2-C≡C-CH3
14.
The pKa of ethyne is approximately:
A.
50
B.
44
C.
16
D.
25
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ANSWER :
D. 25
15.
Reaction of ethyne with ammoniacal cuprous chloride gives:
A.
Black precipitate of cupric oxide
B.
Yellow precipitate of cuprous chloride
C.
Red precipitate of copper acetylide
D.
White precipitate of silver acetylide
😑 View Answer Rough Work Error
ANSWER :
C. Red precipitate of copper acetylide
16.
Acetylene reacts with ammoniacal silver nitrate to form:
A.
Silver oxide (black)
B.
Silver acetylide (white precipitate)
C.
Silver mirror
D.
No reaction
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ANSWER :
B. Silver acetylide (white precipitate)
17.
Which catalyst is used in the partial hydrogenation of alkynes to give cis-alkenes?
A.
Pt/PtO2
B.
Raney nickel
C.
Wilkinson's catalyst
D.
Lindlar's catalyst (Pd/CaCO3 poisoned with PbOAc or quinoline)
😑 View Answer Rough Work Error
ANSWER :
D. Lindlar's catalyst (Pd/CaCO3 poisoned with PbOAc or quinoline)
18.
Reduction of an internal alkyne with Na in liquid NH3 gives:
A.
Alkane
B.
A mixture of cis and trans
C.
trans-Alkene
D.
cis-Alkene
😑 View Answer Rough Work Error
ANSWER :
C. trans-Alkene