how do you know if something is polar or non-polar?

Question

For example CHCL3 or Ethanol or SF4...ya know, solvents and solutes and stuff like that?

gosh...I hope im making sense... :p


For example one of my probs. was to circle the solute that will dissolve to a greater extent at room temp.

solvent: Water (H2O)
solute choices: CHCL3 or CCl4

Answer 1

CHCl3: first you must draw the molecule. You´ll see that CCl4 forms a tetrahedron, so all the bonds dipole moments cancel each other out. But, in CHCl3, one of the Cl atoms is replaced by H and the overall dipole moment for the molecule is not 0, hence it is more polar.