CHEM 6B Lecture Notes - Lecture 16: Intermolecular Force, R136, Ion

• School: UCSD
• Department: Chemistry and Biochemistry
• Course: CHEM 6B
• Professor: Christina Johnson

Document Summary

Many of the examples we have used have been monoprotic where there is only 1 h+ lost or gained. (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) However there are also polyprotic acids and bases. (this has a ka) -h+ (this is a much harder hydrogen to lose) so2- Therefore there are different ka for each dissociation. Ka1 will always be significantly larger than ka2. H2n-ch2-ch2-nh2 +h+ (kb1) h3n+-ch2-ch2-nh2 +h+ (kb2) h3n+-ch2- It"s much easier to add a positive to a neutral than it is to add a positive to a positive. Ka1= 5. 9x10-2 ka2=6. 5x10-5 (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) The problem with a salt is that it could go both ways. We have to determine which is stronger kb or ka ph= (pka1+pka2) The most important thing in this chapter will be intermolecular forces.