Hello there,
I am lost when it comes to pH. Please help me with the following problems asap. I don't know how to do them

1) What is the isoelectric point of the tripeptide Ala-Glu-Asn?

2) If you add 1ml of .2 N NaOH to 100ml of .02 M phosphate buffer, pH 7.0, what would be the resulting pH when pKa(2) = 6.7

3) Calculate the pH of 100ml .08% (w/v) NaOH. If you now add 100ml of .02N HCl to the above solution, what would be the pH?

Go here:
http://us.expasy.org/tools/pi_tool.html

Ala-Glu-Asn in the single letter code is AEN

Paul