Lesson 1: Purity/ Formulations

Question 1

What is a “pure substance” in chemistry?

Answer 1

• In chemistry, a pure substance is a single element or compound, not
  mixed with any other substance.

Question 2

True or False

Pure substances melt and boil at varying temperatures.

Answer 2

• False.
• Pure substances melt and boil at specific temperatures.
• Impure substances melt/ boil at varying temperatures as the different elements/ compounds in them will melt/ boil at different points.

Question 3

What is a “pure substance” in everyday language?
Give an example of a substance that would be considered pure in everyday life.

Answer 3

• In everyday language, a pure substance can mean a substance that
  has had nothing added to it, so it is unadulterated and in its natural
  state, eg pure milk.

Question 4

Are mixtures pure or impure?

Answer 4

• Impure.
• Contain more than one element/ compound.

Question 5

What is a formulation?

Answer 5

• A formulation is a mixture that has been designed as a useful product.
• It contains many chemicals each of which has a particular purpose.

Question 6

How are formulations made?

Answer 6

• Formulations are made by mixing the components in carefully measured quantities to ensure that the product has the required properties.

Question 7

Give 7 examples of formulations.

Answer 7

1.) Fuels.
2.) Cleaning agents
3.) Paints
4.) Medicines
5.) Alloys
6.) Fertilisers
7.) Foods.