[hmok]

For Soapy detergent made from fats:
C(n)H(2n+1)COO-Na+

I wonder when there are some long long chain fatty acids (some sticky fat),
long chain detergent seem to dissolve better as they are more similar due to their long chain.
But short chain detergent seem to have more surface area contacting with the target.
Which one will better dissolve the long chains? How should I consider?

Besides, for a soapy detergent to form soap (or foam, I don't know which is a better expression), a longer chain soap or a shorter chain soap will make it easier and why?

[hmok]

Please help

[Arkcon]

Please help

Please calm down.  From the time point of your messages, you post when many of us are asleep.

Here's a scholarly article which begins to answer your question.  http://www.baruch.cuny.edu/wsas/academics/natural_science/chm_1000/9_soap.doc    Briefly, many of your initial conclusions are simply false.  You might want to re-evaluate them one at a time, comparing your facts with your textbook, to see if you can pull together something that you can use.