Dissolving

When you stir sugar into water, the sugar seems to disappear. But it is still there. The sugar has dissolved. Its tiny particles have spread out and mixed evenly with the water particles. The liquid that does the dissolving is called the solvent. The substance that dissolves is called the solute.

How Dissolving Works

When a solute like sugar is placed in a solvent like water, the water molecules pull apart the sugar molecules. The sugar particles spread evenly throughout the water. You can still taste the sugar even though you cannot see it. Stirring and heating speed up dissolving because they help break apart the solute faster.

What Dissolves and What Does Not

Not everything dissolves in water. Sugar, salt, and baking soda dissolve well. Sand, oil, and wax do not dissolve in water. Different solvents dissolve different things. Nail polish does not dissolve in water, but it dissolves in nail polish remover. Scientists say like dissolves like.

Fun Facts

• Water is called the universal solvent because it dissolves more substances than any other liquid.
• Hot water dissolves sugar about twice as fast as cold water.
• The ocean has about 35 grams of dissolved salt in every liter of water.

Did You Know?

There is a limit to how much of a substance can dissolve in a liquid. When the liquid cannot hold any more, it is called a saturated solution. If you add more solute, it just sits at the bottom!