The compound C3H4 has a triple bond, which is indicated by its reaction with(a) Bromine water(b) Baeyer's reagent(c) Fehling solution(d) Ammoniacal silver nitrate

The compound C3H4 is an alkyne due to the presence of a triple bond. We can identify this through the following reactions:

(a) Bromine water: Alkynes decolorize bromine water due to the addition reaction, which results in the formation of a dibromo alkane. If the bromine water remains colored, it indicates the absence of a triple bond.

(b) Baeyer's reagent: Baeyer's reagent (dilute alkaline KMnO4 solution) is used to identify unsaturated hydrocarbons. Alkynes react with Baeyer's reagent to form a diol, which results in the decolorization of the purple KMnO4 solution. If the solution remains purple, it indicates the absence of a triple bond.

(c) Fehling solution: Fehling's solution is used to test for the presence of aldehydes or reducing sugars, not for the presence of triple bonds. Therefore, it is not applicable in this case.

(d) Ammoniacal silver nitrate (Tollens' reagent): This is used to test for the presence of aldehydes, not for the presence of triple bonds. Therefore, it is not applicable