"Like dissolves like" is an expression used by chemists
to remember how some solvents work. It refers to "polar" and "nonpolar"
solvents and solutes. Basic example: Water is polar. Oil is non polar.
Water will not dissolve oil. Water is polar. Salt (NaCl) is ionic (which
is considered extremely polar). Like dissolves like, that means polar dissolves
polar, so water dissolves salt.
Polar substances WILL dissolve in
Polar substances
Non-polar substances WILL dissolve in
nonpolar substances
Non-polar substances WILL NOT dissolve in polar substances.
Look at the layers in this video
Solvents
Solvent
Polarity
Ethyl acetate
nonpolar
water
polar
chloroform
nonpolar
Solutes
Solute
Polarity
Iodine
nonpolar
copper(II)sulfate
ionic (very polar)
Molecule-Ion Attractions
This is how water and ions attract. The hydrogen's of water align
themselves towards the negative ion (anion), surround it and takes
it away.. If the ion is a positive ion (a cation) the oxygen of the
water align themselves towards the ion, surround it and takes it
away.
