what is the significance of the statement "like dissolves like"?

Question

and what does the "like" refer to? I am so confused!

Answer 1

It refers to the polarity of the molecules in a substance. A polar substance will dissolve in a polar substance but not in a non-polar substance. A non-polar substance will dissolve in a non-polar substance but not in a polar substance. This is why oil and water don't mix. Water is a polar molecule and oil is non-polar.