9.7 - Properties due to Polarity
One of the easiest properties to see regarding polarity is melting and boiling points. The more polar a molecule is, the greater its attraction to other molecules like it. This means that they will stick together tightly even if given a lot of energy. Ionic molecules are normally solid at room temperature. As a matter of fact, it can take a lot of energy to melt many of them (>1000°F). NaCl is a perfect example.
Polar molecules like water are liquid at room temperature. They have a strong attraction to each other, but not as strong as ions. Molecules that are nonpolar do not have this attraction. The only thing that keeps them together is their size. Larger non-polar molecules like gasoline can be a liquid at room temperatures, but become a gas very easily. Most small. nonpolar molecules (CH4) are gases for a very long time. N2 becomes a liquid at -196°C (-320°F).
Another property easily seen between polar and nonpolar molecules is solubility. This is the tendency to dissolve into solutions. The general rule of solubility is Like Dissolves Like. This means that polar things dissolve polar things, while nonpolars dissolve nonpolars. Water (polar) and oil (nonpolar) don’t mix.
Polar molecules like water are liquid at room temperature. They have a strong attraction to each other, but not as strong as ions. Molecules that are nonpolar do not have this attraction. The only thing that keeps them together is their size. Larger non-polar molecules like gasoline can be a liquid at room temperatures, but become a gas very easily. Most small. nonpolar molecules (CH4) are gases for a very long time. N2 becomes a liquid at -196°C (-320°F).
Another property easily seen between polar and nonpolar molecules is solubility. This is the tendency to dissolve into solutions. The general rule of solubility is Like Dissolves Like. This means that polar things dissolve polar things, while nonpolars dissolve nonpolars. Water (polar) and oil (nonpolar) don’t mix.
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