Propyne and propene can be distinguished bya) ...
The terminal hydrogen is acidic in propyne so it react with ammoniacal silver nitrate... while propene has no acidic hydrogen so it won't react with ammoniacal silver nitrate.... so it can be distinguished by this test so, option D is right.
Propyne and propene can be distinguished bya) ...
Answer:
To distinguish between propyne and propene, we can use the reaction with AgNO₃ in ammonia (option D) as a test. This reaction is also known as the Tollens' test or the silver mirror test.
The Tollens' Test:
In the Tollens' test, the alkyne propyne reacts differently from the alkene propene due to the presence of the triple bond in propyne.
Reaction of Propyne:
When propyne reacts with AgNO₃ in ammonia, it undergoes oxidation to form a carboxylic acid and a silver mirror is formed on the inner side of the test tube.
C₃H₄ + AgNO₃ + 2NH₃ → C₃H₄O₂ + Ag + 2NH₄NO₃
The silver mirror is formed because the aldehyde (C₃H₄O₂) produced in the reaction reduces the silver ions (Ag⁺) present in AgNO₃ to metallic silver (Ag), which gets deposited on the inner side of the test tube.
Reaction of Propene:
On the other hand, when propene reacts with AgNO₃ in ammonia, it does not undergo oxidation to form a carboxylic acid. Therefore, no silver mirror is formed and the reaction does not take place.
C₃H₆ + AgNO₃ + 2NH₃ → (no reaction)
Conclusion:
Based on the reaction with AgNO₃ in ammonia, we can distinguish between propyne and propene. If a silver mirror is formed, it indicates the presence of propyne. If no silver mirror is formed, it indicates the presence of propene. Therefore, the correct answer is option D - AgNO₃ in ammonia.
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