CGP C8

Question 1

Purity

Answer 1

. Usually when you refer to a substance as being pure you mean that nothing has been added to it, so it’s in its natural state

. In chemistry, a pure substance is something that only contains one compound or element throughout - not mixed with anything else

Question 2

Boiling / Melting point

Answer 2

. A chemically pure substance will melt or boil at a specific temperature
. You can test the purity of a sample by measuring its melting or boiling point and comparing it with the melting or boiling point of the pure substance
. The closer the measured value is to the sample, the purer the sample is

Question 3

Impurities

Answer 3

. Impurities in your sample will lower the melting point and increase the melting range of your substance

. Impurities in your sample will also increase the boiling point and may result in your sample boiling at a range of temperatures

Question 4

Formulations

Answer 4

. Formulations are useful mixtures with a precise purpose that are made by following a ‘formula’. Each component in a formulation is present in a measured quantity, and contributes to the properties of the formulation so that it meets its required function.

Question 5

Formulations in the pharmaceutical industry

Answer 5

. Formulations are really important in the pharmaceutical industry. For example, by altering the formulation of a pill, chemists can make sure it delivers the drug to the correct part of the body at the right concentration, that its consumable and has a long enough shelf life

Question 6

Formulations in everyday life

Answer 6

. In everyday life, formulations can be found in cleaning products, fuels, cosmetics, fertilizers, metal alloys and even food and drink

Question 7

Formulation information

Answer 7

. When you buy a product, you might find that it has information about its composition on its packaging. for example, the ratio or percentage of each component. This tells you the products formulation. It also lets you choose a formulation with the right composition for your particular use

Question 8

What is chromatography

Answer 8

. Chromatography is an analytical method used to separate the substances in a mixture. You can use it to identify the substances

. There are different types of chromatography but they all have two phases:
. A mobile phase - where the molecules can move. This is always a liquid or a gas
. A stationary phase - where the molecules can’t move. This can be a solid or a really thick liquid