What are materials made of?
            2. When materials mix
logo
last page  page 10 Next page
Solutions and suspensions
When you add a small amount of sugar to water the solid disappears. We say that it dissolves. The water particles are attracted to the sugar particles. Each sugar particle is surrounded by water particles which separate it from neighbouring sugar particles. Instead of there being a very large, visible clump of sugar particles, the sugar particles are spread out. Although they are still there, we can’t see them any more. We say that sugar is soluble in water and has formed a solution.
Dissolving nail varnish sequence
Picture 2.4 Nail varnish is not soluble in water. But propanone dissolves it because its particles break up the varnish.

A suspension
Nail varnish does not dissolve in water because the water particles are not attracted to the nail varnish particles. They remain clumped together and we can still see the nail varnish in the water. We say that the nail varnish is insoluble in water and has formed a suspension.
Making a solution

However, nail varnish does dissolve in a liquid called propanone. Propanone particles are attracted to the nail varnish particles. They surround the nail varnish particles and keep them apart from other nail varnish particles. They can’t clump together.

Nail varnish is soluble in propanone and forms a solution.
Nail varnish is not soluble in water and forms a suspension.

Nail varnish
Picture 2.5 . Nail varnish remover. The main solvent is propanone - also known as acetone.

Solutes and solvents
Scientists use some general words to describe what happens when a solid dissolves in a liquid to form a solution. The solid is called the solute and the liquid it dissolves in is called the solvent.
Question 9
a) If 3 grams of solid dissolves in 100 grams of liquid, what is the total mass of the solution formed?

b) Look at the table below. For each of the solutions, decide which material is the solute and which is the solvent. Make your choices using the drop down lists.

solute solvent
sugar solution
Nail varnish
top of page top of page last page Next page