LEARNING TASK CHEM II
ONLINE TREASURE HUNT
Temperature vs. Solubility
Solubility Graph
Subject teacher
Ethielyn E. Taqued
Cordillera Regional Science High School
Introduction:
The solubility of a given solute in a given solvent typically
depends on temperature. For around 95% of solids, the solubility
increases with temperature in the temperature range from about
ambient to 100 °C. In liquid water at high temperatures particularly
approaching critical temperature, the solubility of ionic solutes tends
to decrease due to the change of properties and structure of liquid
water.
When the temperature of a saturated solution in the presence
of some excess solute is raised, the excess solid usually dissolves. If
the system then cools slowly and undisturbed to its original
temperature, the excess solute does not always immediately
crystallize but the solution is referred to as supersaturated solution
for it holds more solute than it can theoretically holds.
This activity will lead you to understand that a diagram or
graph can assist us in determining the theoretical saturation point of
a solution with a given 100 g water solvent in relation to the
solubility properties of the solute.
Working by pairs, choose a student you have not worked with before, find
the answers to the following questions on the amount of solute needed to
reach a saturated solution. The answers are to be found on the websites listed
below. Click on the URL provided in this activity. Read each website
carefully take note that each website is used to answer one question. Write
your answers to the questions on Word document with your name and your
partners’ name. Then, you may move to answer the Big Question which will
lead you to understand its application to the phenomenon observed around
us. Be sure to work together and complete the activity in one hour. When
you’re done, you should have an overview of crystallization of solutes in
supersaturated solutions and the characteristic of a dynamic equilibrium.
Small Questions/ Concept Formation:
1. How will you differentiate an unsaturated, saturated and supersaturated solution?
2. Which among the three types of solutions can be considered in its dynamic state? Why?
3. Why is it necessary to know the type of solute to be dissolved? How will this affect
solubility?
4. What are the variables found in the graph?
5. What important information you can draw from a solubility diagram/ curve?
Web Resources
DYNAMIC EQUILIBRIUM
http://en.wikipedia.org/wiki/Dynamic%5Fequilibrium
SATURATED SOLUTION
http://www.coolschool.ca/lor/CH12/unit3/U03L04.htm
SOLUBILI TY GRAPH
http://www.thesciencedesk.com/sgsolubilitygraph.htm
MULTIPLE-CHOICE EXERCISE
http://www.sciencegeek.net/Chemistry/taters/solubility.htm
CONCEPT OF SOLUBILITY CURVE
http://en.wikipedia.org/wiki/Solubility
MINERAL FORMATION
http://www.britannica.com/EBchecked/topic/383726/mineral-deposit/82171/Formation-ofmineral-deposits
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Prepare an online presentation for discussion. For those groups with
power point presentation must not go over 5 slides.
Activity 1 For groups 1-4
Draw a graph to show the solubility of potassium nitrate, the figures are given below. The
solubility goes up the side, the temperature goes along the bottom. Draw a smooth curve
through the points on the graph:
Temperature in oC
0
20
40
60
80
100
Solubility in g/100g water
13
32
64
110
169
246
Activity 2: For groups 5-8
Complete the table by filling in the difference column and answer the questions that
follow.
Name of
chemical
at
solubility solubility difference
at 15oC at 80oC
Which is the least soluble at
Copper (II)
sulphate
18.8
55
Potassium
chloride
32.8
51.3
Potassium
nitrate
25.8
169
Sodium
carbonate
16.4
45.8
sodium chloride
35.9
38.4
15oC? Which is most soluble
15oC?
Which one is most soluble at
80oC?
Which one increases in
solubility by the most?
Which one increases in
solubility by the least
Activity 3 For groups 9-12
How are mineral deposits formed around edges of hot springs?
Your total working time is 30 minutes and 30 minutes for
discussion…..Have a nice time looking for the Treasure…!!!!!