Question

Question:Propose two possible structures for a hydrocarbon having an exact mass of 96.0939 that forms ethylcyclopentane upon hydrogenation with H2 and Pd-C.

Short answer

Answer

Two possible structures:

Step-by-step solution

Hydrogenation using  H2,Pd-C

Compounds having pi-bonds can be hydrogenated upon treatment with hydrogen in the presence of a palladium catalyst. The Pd-C catalyst used in the hydrogenation process acts as an adsorbent surface, and the syn-addition of hydrogen to the pi-bond occurs on this surface.The general reaction is given below:

Determination of possible structures

The structure of ethyl cyclopentane is given below:

Structure of ethyl cyclopentane

The exact mass of ethyl cyclopentane is 98.1095 amu.

Since ethyl cyclopentane is the product formed upon hydrogenation, it can be assumed that the starting material has pi-bonds that are being reduced.

Upon removal of 2 hydrogen atoms, each having an exact mass of 1.00783, the mass becomes 96.0939.

Thus, the possible structures of the compound which give ethyl cyclopentane upon hydrogenation are:

Possible structures that give ethyl cyclopentane upon hydrogenation