Everything Science Grade 10

2.2 CHAPTER 2. CLASSIFICATION OF MATTER

Example 1: Mixtures

QUESTION

For each of the following mixtures state whether it is a homogeneous or a hetero-

geneous mixture:

a. sugar dissolved in water

b. flour and iron filings (small pieces of iron)

SOLUTION

Step 1:Look at the definition

We first look at the definition of a heterogeneous and homogeneous

mixture.

Step 2:Decide whether or not you can see the components

a. We cannot see the sugar in the water.

b. We are able to make out the pieces of iron in the flour.

Step 3:Decide whether or not the components are mixed uniformly

a. The two components are mixed uniformly.

b. In this mixture there may be places where there are a lot of iron filings and

places where there is more flour, so it is not uniformly mixed.

Step 4:Give the final answer

a. Homogeneous mixture.

b. Heterogeneous mixture.

Activity: Making mixtures

Make mixtures of sand and water, potassium dichromate and water, iodine and

ethanol, iodine and water. Classify these as heterogeneous or homogeneous. Give

reasons for your choice.

28 Chemistry: Matter and Materials