How to tell which compound would likely dissolve in water or gasoline?

Question

I have a quick question and would like some tips as to how to tell a compound as to whether it would dissolve more in water or gasoline. Such as Choloroform(CHCl3), Na2SO4, KCl, and BaSo4

I would greatly appreciate anyone's help with this!

Answer 1

We've to get this clear first. Water is a polar solvent, gasoline is a non-polar solvent. By the principal of like-dissolves-like, polar molecules will dissolve in water, for example, NaCl; while non-polar molecules will dissolve in gasoline, for example, fats, phosholipids, alkanes, alkenes etc.

For the question you've asked,
Chloroform is a polar compund because Cl draws electrons from the carbon center and making Cl atoms have a higher concerntration of electrons. Hydrogen atoms in water carry a partially positive charge and hence are attracted to Cl molecule. Hence it is soluble in water.

Na2SO4 is soluble in water. This is because it is actually 2 Na+ ions attached to SO4(2-) ions. Na+ ions get attracted to oxygen atoms in water which has a partially negative charge and SO4(2-) ions gets attracted to hydrogen atoms in water which has a partially positive charge.

KCL is soluble in water because Cl atoms draws electrons from K. Follow the same reasoning as chloroform.

For BaSO4, it is insoluble in water. Only barium nitrate dissolves in water. Other barium salts do not.

Hope this helps! =)

Answer 2

All of the answers above are right, to a point. However, I would caution that chloroform is not a very polar compound. Yes, the chlorine would draw electrons from the carbon to yield a polar bond but remember that there are three such polar bonds around this carbon and the dipole moments of two of them cancel each other out, leaving only one and that's not enough to make it very polar. Chloroform is miscible with gasoline but not water.

Otherwise, you have salts which are decidedly polar because they are ionic. These will dissolve in water but not gasoline.

Answer 3

Remember "Like dissolves like". So, water is a great solvent, but polar compounds will dissolve best in polar solvents, non-polar in non-polar solvents, etc, etc, etc

Answer 4

Water is called the universal solvent.It is obvious that choloroform is going to dissovle more in water than in gasoline.