pH 3.3 , 3.7% 酸度 跟 29% 的酒精比較, 哪種會比較容易溶解油脂?

I would say the alcohol MIGHT be able to dissolve fatty acids better than pH 3.3 or 3.7. Simply because fatty acid is a, well, fatty chain full of carbons and hydrogens! A hydrocarbon chain, which means it is very polar and will require a polar solvent to dissolve it (ie. to take fatty acid into the organic layer).
Now this also depends on what sort of fatty acid we are talking about - some might be able to protonate under acidic conditions and hence, dissolves in acid! BUT this is quite unlikely because 1) fat doesn't dissolve in water due to lack of hydrogen bonding with H2O 2) fat is just too polar! (ie. it's too fatty, lipophilic).
Hope you understand what I mean..

now i understood it very clear