Question

Shouldn't ethylene should be more acidic? It has a C=C bond, so the density of electron cloud would be higher in the areas of the double bond while the C-H single bond have way less electron density. This, plus the fact that carbon has higher electron negativity than phosphorus should mean ethylene is more acidic as C-H bond will be more weakened than P-H bond and thus, C-H bond will break relatively easily, releasing H+ ions more frequently.

However that seems to be not the case (as discussed in this question Is ethylene more acidic than phosphine?).

Why so? Or am I wrong? Any help or discussion is welcomed. Thanks!

Answer 1

The acidity of a compound is determined by its ability to release hydrogen ions (H+). Ethylene is not more acidic than phosphine.

Step-by-step explanation:

The acidity of a compound is determined by its ability to release hydrogen ions (H+) when dissolved in water. In the case of ethylene, the C-H bonds are relatively strong due to the low electronegativity difference between carbon and hydrogen, resulting in a low tendency to release H+ ions.

On the other hand, the P-H bond in phosphine is weaker due to the higher electronegativity difference between phosphorus and hydrogen, making it more acidic than ethylene. Therefore, ethylene is not more acidic than phosphine.