BLOOMING HERITAGE SCHOOL
Solutions
and
Solubility
YEAR 8 SCIENCE
WK 4: LESSON 1
By
Ms Chinyere
Learning Objectives:
 Use particle theory to describe the difference between dilute
and concentrated solutions
 Make solutions of different concentrations
 Compare solubility of various solutes.
 Describe the solubility of a solute at different temperature
Keywords
 Dilute solution
 A solution in which a small mass of solute is dissolve in a large volume
 Concentrated solution
 A solution in which a large mass of solute is dissolved
 Soluble
 Substance that would dissolve in a given solvent
Keywords
 Insoluble
 Substance that cannot dissolve in a given solvent
 Solubility
 A measure of how soluble a solute is in a
particular solvent.
 Saturated solution
 A solution in which no more of the solute will
dissolve
STARTER
Getting Started….. Page 45

Think about the meaning of the words ‘Solvent’,
‘Solute’ and ‘Solution’ with absolute quietness.

In 1 minutes discuss your thought with a partner

In the piece of paper before you, write the
differences between solvent, solute and solution.

Get ready to share ideas
Solutions
 How can you identify a dilute or a
concentrated solution?
 More particles of the solute are dissolved
in a concentrated solution than in a
dilute solution.
Solubility
 How can you identify a soluble
and insoluble substance?



Soluble substances are completely
dissolve in water or are entirely mixed
in water throughout the solution.
Insoluble substances do not dissolve
completely even after prolonged
stirring.
Sugar, Vinegar, and Common salt are
examples of soluble substances.
Comparing Solubility





If you keep adding a soluble solid to
a beaker of water
There comes a point where no more
of the solid will dissolve
A saturated solution is formed
To compare the solubility of
different solutes,
measure how much of each of the
solute will dissolve in the known
solvent.
Temperature and Solubility

How can you make a solute
dissolve more quickly in a
solvent?

Most solutes will dissolve more
quickly and easily in hot water than
in clod water
In other words, as the temperature
increases, the solubility of most
solutes also increases.

Solubility Curves
Remember, that Solubility is the amount of
solute that will dissolve in a given amount of
solvent at a specific temperature.
For this curve,

X-Axis: Temperature

Y-Axis : How Much Solute Dissolves in
100g of Water

Various Lines: Each line represents a
different solute.
What is the
solubility of
potassium nitrate
at 80C ?
170g/100cm3
 What substance has a
solubility of 90 g/100
cm3 in water at a
temperature of 25C ?
 Sodium
nitrate
What substance has
a solubility of 200
g/100 cm3 of water
at a temperature of
90C ?
 Potassium
nitrate
At what temperature
will sodium nitrate
have a solubility of
95g/100 cm3 ?
 30C
How would you
describe the trend
for the solubility of
all five solutes?
As the temperature
increases, the
solubility increases
except for sodium
chloride.
Other solvents
 Water is a
universal solvent
but not the only
solvent
 See other different
types of solvents
Homework
Unit 2 of the work book
Page 21 -32
Plenary –
Explain the difference between…….
 Work in pairs
 Explain the difference in particle terms,
between a concentrated solution and a
less concentrated solution
 You must use the words ‘’solvent’’,
‘’solute’’ and ‘’Particle’’.
Success Criteria
• I can describe how to make solutions at
different concentrations
• I can compare the number of solute
particles in solutions of different
concentration
21st Century Skills
Communication
Collaboration
Self Assessment
Critical thinking