13.2 What rule do we use to explain dissolving? What does it mean? Like dissolves like rule. This means that polar and ionic compounds dissolve in polar solvents whereas non-polar compounds dissolve in non-polar solvents. What are the two factors that determine if one substance will dissolve in another? 1) Attractive forces between molecules, 2) a tendency for randomness. Give examples of nature’s tendency for randomness.The diffusion of gasses (e.g. perfume in a room, or the mixing of two gasses), the diffusion of liquid in liquid (e.g. a drop of food colouring in water). Why does alcohol easily dissolve in water? Because the attraction of water (polar) to alcohol (polar) is about the same as the attraction of water to water. Why does benzene not dissolve in water? Because the attraction of water (polar) to benzene (non-polar) is very different from the attraction of water to water. Think about it this way: whenever two or more molecules of water bump into each other, they will be attracted (both have partial charges). Any benzene molecules in the area will not be attracted to the water, and therefore will be pushed out of the way. Why does benzene (non-polar) dissolve in CCl4(non-polar)? Both have weak attractive forces, thus they can easily leave their own kind to mix with each other. The drive for randomness wins out over any differences in attractive forces.
This is the end of the preview.
access the rest of the document.