Mixtures

Keywords

Mixture, compound, element, atom, substances, homogenous, heterogenous, uniform distribution.

Introduction

We know that elements are made up of atoms, and that a compound is made of two substances that chemically bond together and form a new substance. But what about a mixture?

What is it?

Let's look at how we make a cup of tea. We boil a kettle, and add the hot water to a cup that has a tea bag in it. The process of diffusion happens when the tea bag allows the interaction between the tea leaves and the water. This then makes the tea.

We can add sugar to this mixture and it will be a lovely cup of tea.

A mixture is the collection of two or more substances that can still be split apart. In the case of the cup of tea and sugar, we can remove the sugar by way of heating up the liquid again. The sugars will literally burn off.

Interesting fact: a mixture can be either homogenous or heterogenous. A homogenous mixture is one that is uniformly combined and distributed, whereas a heterogenous mixture is one that is the opposite.

Other examples of mixtures include:

• dirt and water (mud)
• water and salt (sea water)
• smoke and fog (smog)
• zinc and copper (brass)
• lead and tin (solder)
• orange juice and champagne
• cereal and milk
• plasma, white blood cells, red blood cells, platelets (blood)

Types of Mixture

There are two types of mixture. Let's look at them here:

Heterogenous Mixture: a mixture that is heterogenous has both components, but the dispersal is not uniform. An example of this is sand mixed with salt.

Homogenous Mixture: a mixture that is homogenous has the same properties and combination throughout their mass. This means they are uniform and is the same all the way through. An example of this is water.

Separation Processes

There are several ways to remove the components of a mixture, including:

• evaporation (crystallisation)
• filtration
• distillation
• paper chromatography