Do negatively charged amino acids dissolve in water?

Amino acids are generally soluble in water and insoluble in non-polar organic solvents such as hydrocarbons. This again reflects the presence of the zwitterions. In water, the ionic attractions between the ions in the solid amino acid are replaced by strong attractions between polar water molecules and the zwitterions.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.