Purity

Question 1

What does it mean if a substance is pure?

Answer 1

It’s completely made up of a single element or compound.

Question 2

What is a mixture?

Answer 2

When you have more than one compound present, or different elements that aren’t all apart of a single compound.

Question 3

Is air pure or impure?

Answer 3

Air is actually impure, as it is a mixture of nitrogen, oxygen, argon, carbon dioxide, water vapour and various other gases.

Question 4

What is an example of a useful mixture?

Answer 4

Alloys.

Question 5

What type of melting and boiling points do pure substances have?

Answer 5

Specific, sharp melting and boiling points.

Question 6

What type of melting and boiling points do mixtures have?

Answer 6

They will melt and boil gradually over a range of temperatures.

Question 7

How can you measure the melting point of a substance?

Answer 7

You can use melting point apparatus.

Question 8

What does melting point apparatus do?

Answer 8

Heat up a small sample of a solid very slowly, so you can observe and record the exact temperature that it melts at.