Science Quiz on Mixtures and Solutions

Which of these is a mixture:

• oxygen

• air

• sugar

• table salt

Pure water is:

• rain

• water which is clean enough to drink

• water which runs off the hills

• water with nothing else in it

A mixture is:

• just one substance, like pure salt

• 2 or more things mixed together

• a lot of the same thing put together

• 2 or more different things chemically combined

What happens at the boiling point of a substance?

• A liquid changes into a gas

• A solid changes into a liquid

• A liquid changes into a solid

• A gas changes into a liquid

When you add salt to water:

• the salt is a solvent

• the water is the solute

• the salt is the solute

• the water is the solution

Filtering cannot be used to separate:

• sand from a mixture of sand and water

• sugar from sugar solution

• tea leaves from a pot of tea

• leaves from a mixture of leaves and pond water

Only 20g of a salt will dissolve in 100g of water at room temperature. If you use hot water instead:

• less than 20g will dissolve

• only 20g will dissolve

• more than 20g will dissolve

• no salt will dissolve

Which of these does not involve chromatography:

• making petrol from oil

• identifying the food dye in orange squash

• DNA fingerprinting

• identifying paints or inks found at a crime scene

The two steps in distillation are:

• filtering followed by evaporation

• evaporation followed by condensation

• condensation followed by filtering

• filtering followed by condensation

The melting point of a pure substance is:

• higher than the boiling point

• the same as the boiling point

• lower than the freezing point

• the same as the freezing point