Filtration | Starter Quiz | Oak National Academy

Which substances are insoluble (do not dissolve) in water?

• sugar

• sand

• salt

• flour

Answer explanation

Sand and flour cannot dissolve in water. Sugar and salt can dissolve.

A ___ is a material that contains two or more different substances, which can be physically separated.

Answer explanation

A mixture is a material that contains two or more different substances, which can be physically separated.

What mixture is formed when a substance dissolves in a liquid?

• solution

• suspension

• insoluble

• soluble

• solvent

Answer explanation

A solution is formed when a soluble substance (solute) dissolves in a liquid (solvent). This is a mixture.

Match the following words to their meaning.

• Soluble

• The liquid in which a solute is dissolved to form a solution.

• Solution

• A substance which cannot dissolve in a liquid.

• Solvent

• To divide something into its different parts.

• Insoluble

• A substance which can dissolve in a liquid.

• Separate

• Formed when a solute dissolves in a solvent.

Answer explanation

A soluble substance is one which can dissolve in a liquid. An insoluble substance is one which cannot. When you separate something you divide it into its different parts. A solvent is the liquid in which a solute is dissolved to form a solution.

Which of the following are mixtures?

• 'pure' orange juice

• oxygen

• air

• sodium chloride (salt)

• carbon

Answer explanation

Orange juice and air are mixtures that contain two or more different substances. Oxygen, salt and carbon are pure substances made up of only one type of chemical.

When a solid substance is insoluble, it can still form a mixture with a liquid. This mixture is called a ...

Answer explanation

A suspension is a mixture of an insoluble solid and liquid, in which the solid particles are dispersed in the liquid and settle upon the mixture standing.