OpenStax-CNX module: m20271
1
Separation of mixtures
∗
Siyavula Uploaders
This work is produced by OpenStax-CNX and licensed under the
†
Creative Commons Attribution License 3.0
1 NATURAL SCIENCES
2 Grade 8
3 MATTER: CLASSIFICATION
4 Module 22
5 SEPARATION OF MIXTURES
• Dierent methods of separation are used for dierent mixtures.
The educator will explain and may demonstratethe METHODS that are listed:
•
•
•
•
•
Sorting by hand sort according to size, form and colour
Filtration one of the substances is soluble
Evaporation dissolves in water and water evaporates leaving salts behind
Separating funnel two liquids with dierent densities
Distillation use a Liebig condenser to heat, evaporate and condense
APPARATUS:
Sketch of ltration and distillation apparatus and a separating funnel.
Figure 1
∗ Version
1.1: Mar 12, 2009 7:30 am -0500
† http://creativecommons.org/licenses/by/3.0/
http://cnx.org/content/m20271/1.1/
OpenStax-CNX module: m20271
2
5.1 Activity: Select a method of separation
Select and write down a method of separation for the following mixtures:
Sand and salt
Beans and peanuts
Squash syrup and water
Oil and water
Dierent coins
5.2 Assignment
with sketches of the method you would follow to:
a) separate sand from salt.
b) separate squash syrup from water.
1. Which method would you use to obtain fresh water from sea water?
2. Why is this method not used to add to fresh water sources?
3. What is the dierence between a distillate and a ltrate?
4. Explain what fractional distillation is and name two industries in which it is used.
Give a step by step explanation
5.3 Pro ject
How would you separate water and alcohol?
• Also nd out something about fractional distillation.
• Suggestion: use what you have found out about the boiling point of substances (learning unit 3).
• Sketches form an important part of a pro ject !
• Submit the project on the date set by the educator.
Assessment of the project
Were you able to plan the project (AS 1.1), collect data (AS 1.2) and evaluate and communicate your
ndings (AS 1.3), as well as apply knowledge (AS 2.4)?
[LO 1.1; LO 1.2; LO 1.3; LO 2.4]
6 Assessment
Learning outcome 1: Scientic investigations
The learner will be able to act condently on curiosity about natural phenomena, and to investigate
relationships and solve problems in scientic, technological and environmental contexts.
ASSESSMENT STANDARDS: We know this when the learner
1.1 is able to plan investigations;
1.2 is able to execute an investigation and collect data;
• is able to evaluate data and communicate ndings
Learning outcomes 2: Constructing science knowledge
The learner will know and be able to interpret and apply scientic, technological and environmental
knowledge.
ASSESSMENT STANDARD: We know this when the learner
2.4 is able to apply knowledge.
http://cnx.org/content/m20271/1.1/
OpenStax-CNX module: m20271
7 Memorandum
Mixture Method
Sand & salt Filter
Beans & peanuts Manual sorting
Squash syrup & water Distillation
Oil & water Separating funnel
Dierent coins Manual sorting
Sketches the correct apparatus
1.
2.
3.
4.
5.
Distillation
Cost
Distillate uid condenses after distillation
ltrate uid that is ltered
ltering at dierent boiling points, e.g. at oil reneries and in the spirtis (alcohol) idustry.
PROJECT
Alcohol boils at 79ºC fractional distillation removes alcohol; water is left behind.
Regulation of temperature, using a thermometer is very important.
Sketch of how the Lieg condenser is set up is important.
http://cnx.org/content/m20271/1.1/
3