[blurry]

Hello!

I performed an experiment where I left 5 esters of different overall number of carbons (methyl benzoate, ethyl acetate, ethyl formate being 3 examples) in presence of water and concentrated HCl to reach equilibrium (in 9 days). I then titrated the solution against NaOH and did subsequent calculations to derive the equilibrium constant (Kc) values of each ester. What I found was rather interesting: the more carbons an ester has, the lower the Kc value, though not proportionally so. The experiment was done under standard conditions.

My question is, is there any particular reason or justification as to why this is so? Or was this rather just a fluke?

I appreciate any ideas of suggestions you have. Thank you!

[orgopete]

I don't agree with the conclusions nor design of the experiment. I don't think you are measuring the equilibrium constant. How do you know that equilibrium has been reached? I think the equilibrium should shift to virtually complete hydrolysis in all cases, presuming enough water is present. I think your reaction under dilute HCl is giving you a kinetic effect. With the three esters noted, it isn't the number of carbons present, but simply the rate at which those esters should hydrolyze.