Which of the following compounds would you expect to be the most reactive?

A. Ethyne

B. Ethene

C. Methane

D. Ethane

The compound that would be most reactive is Ethyne (answer A)

explanation

Ethyne is the most unsaturated among the four compounds (it has a triple bond between the two carbon atoms).

The triple bond in ethyne is made up of 1 sigma bond and 2π bond. The 2π bond are weaker and can easily break which make Ethyne more reactive than Ethene, methane and Ethane.