|MadSci Network: Chemistry|
Thibaut - Grease doesn't dissolve readily in water due to the difference in polarity between the water, a polar solvent, and the grease, a non-polar solute. Generally speaking, the rule of thumb is "like dissolves like" - that is, polar solvents will dissolve polar solutes and non-polar solvents dissolve non-polar solutes. In polar dissolution, it is mainly a matter of charge "insulation" of the ionic solute by the polar water molecule. In non-polar dissolution the main forces are Van der Waals forces - weak inductive forces between large covalent, non-polar molecules. As for your question about the volume of NaOH. You need to know the density of the sodium hydroxide to calculate the volume required. Try the Handbook of Chemistry or the Handbook or Chemistry and Physics. YOu might also try some of the online chemical databases. Check out the website: http://www.gemlink.com/~rstein/chemhelp.htm for a list of chemical databases.
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