C8: Purity and Formulations

Question 1

In chemistry, what is a pure substance?

Answer 1

A substance that only contains one compound or element throughout - not mixed with anything else.

Question 2

How can you test the purity of a sample?

Answer 2

By measuring it’s melting or boiling point and comparing it to those of the pure substance.

The closer to the actual melting or boiling point, the outer your sample.

Question 3

What do impurities in your sample do?

Answer 3

Lower the melting point and increase the melting range of your substance
Increase the boiling point and may result in your sample boiling at a range of temperatures.

Question 4

What are formulations?

Answer 4

Mixtures with exact amounts of components / Useful mixtures with a precise purpose that are made by following a formula.

Each component is present in a measured quantity & contributes to the properties of the formulation so it meets its required function.

Question 5

Describe the formulation of paints.

Answer 5

Pigment - colour
Solvent - dissolve their components & alter viscosity
Binder (resin) - forms a film that hold pigment in place
Additives - further change the physical & chemical properties of the paint

Question 6

How are formulations important in the pharmaceutical industry?

Answer 6

By altering the formulation of a pill, chemists can deliver the drug to correct part of the body at the right concentration, that it’s consumable and has a long enough shelf life.

Question 7

Where are formulations found in every day life?

Answer 7

Cleaning products 
Fuels
Cosmetics
Fertilisers
Metal alloys
Food and Drink