Q.In the following reaction, HC≡CH (ethyne) treated with dilute H2SO4 / HgSO4 gives product 'X'. Product 'X' will not give a) Tollen's test b) Victor Meyer test c) Iodoform test d) Fehling solution test

Step 1. Ethyne (HC#CH), treated with dilute H2SO4/HgSO4, undergoes Markovnikov hydration through an enol intermediate that tautomerises -- this specific alkyne (acetylene) gives an ALDEHYDE, acetaldehyde (CH3CHO), rather than a ketone.

Step 2. Acetaldehyde, being a genuine aldehyde, DOES give Tollens' test (silver mirror) and Fehling's solution test (blue to red Cu2O), since both exploit the aldehyde's own easy oxidisability.

Step 3. Acetaldehyde also contains the CH3-CO- (here CH3-CHO) fragment needed for a positive iodoform test, since acetaldehyde is the one aldehyde that gives the haloform reaction. …

First identify X from the hydration reaction (acetaldehyde), then recognise that three of the four listed tests are carbonyl/aldehyde tests X WOULD pass, while Victor Meyer's test is a …

• Assuming X is 'an alcohol' because water was a reagent in its formation, and therefore expecting it to give the Victor Meyer test -- the water is consu …