HELP. what are van der waals forces?

Calculate the expected ph values of the buffer systems from the experiments (a,b,c,d), using the henderson- hasselbalch equation, ph-pka+log[a-]/[ha]. use for pka values carbonic acid= 6.37, and acetic acid= 4.75.

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?

Areader can tell that the meaning of “obnoxious” will include “having the quality of something” because of the .a) prefix b)pronunciation c)suffix d) word root