Integrated Science: Mixtures Part 1

MIXTURES PART 1
INTEGRATED SCIENCE

By Elias Chinyanta

A Substance made up of two or more substances that are not chemically combined.

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​DEFINITION

Mixtures of substances that do not mix uniformly.

- Parts of the mixture do not have the same properties.

Examples

1 Soil 2 Salt 3 Fruit salad

4 sand in water 5 Marbles 6 Corks

7 Oil and water 8 Soups and stews

Heterogeneous mixtures:

Mixtures of substances that mix uniformly.

- All parts of the mixture have the same properties
Examples:

1. sugar water (sugar solution) 2. Sea water

3 Air 4. Blood

​Homogeneous mixtures:

TYPES OF MIXTURES

Multiple Choice

GIVE TWO EXAMPLES OF HOMOGENEOUS MIXTURES

• Sand and gravel
• Saltwater, air
• Oil and water
• Sugar and vinegar

Multiple Choice

GIVE TWO EXAMPLES OF HETEROGENEOUS MIXTURES

• Fruit Salad
• Sugar and Water
• Oil and Vinegar
• Salad, Sand and Salt Mixture

SEPARATING MIXTURES

METHODS:

1. Filtration 2. Simple distillation
3. Fractional distillation 4. Magnetisation
5. Evaporation 6. Crystallisation

It is a method of separating insoluble solids from a liquid using a filter paper.
- Insoluble substances: Substances that do not dissolve.
- The mixture of sand and water or the mixture of chalk particles and water can be separated using the process of filtration.
- The filter paper is inserted into the funnel.
- The mixture is poured. - Water molecules will pass through the filter paper as filtrate
- Sand or chalk particles will remain on the filter paper.

FILTRATION

Multiple Choice

When is the filtration method used to separate mixtures?

• When separating gas-liquid mixtures.
• When separating solid-solid mixtures.
• When separating liquid-liquid mixtures.
• When separating solid-liquid mixtures.

- This is the process of vapourising the liquid and condensing the vapour. - It can be used to separate the liquid water from the salt solution. - The liquid has usually a very much lower boiling point than that of a dissolved solid. - The liebig condenser is used to cool the vapour and this vapour is collected as distillate. - The diagram below shows the simple distillation.

SIMPLE DISTILLATION

Multiple Choice

When is it suitable to use the simple distillation method?

• When the components have significantly different boiling points.
• When the mixture is a solid and needs to be separated.
• When the components are soluble in each other.
• When the components have identical boiling points.