INVESTIGATION II, PART 1 Salt Saturation

1
INVESTIGATION II,PART 1Salt Saturation
2
How can you determine the mass (number of grams)
of 50 milliliters (ml) water?What is the mass
of 50 ml of water?
3
Will a solution made with 50 ml of water and a
spoon of salt have the same mass as 50 ml of
plain water? More mass? Less mass? How can
you find out?

4
MATERIALS NEEDEDMake sure all of your materials
are there as your group will be held responsible
for them.

• 1 balance set
• 3 plastic cups (1 labeled S)
• 1 set of masses (1 brown, 2 orange,
  
  
  4 yellow, and 25
  blue)
• 1 syringe
• 1 half liter container
• 1 popsicle stick

5
How can you determine the mass (number of grams)
of salt you put in the water to make the
solution?What is the mass of the salt you added
to the water?
6
When salt and water are mixed the salt will
dissolve making the mixture a solution but does
the salt DISAPPEAR?
Answer
7
We made a salt solution by dissolving a spoon of
salt in 50 ml of water. What do you think would
happen if we put two spoons of salt in 50 ml ?
Would it dissolve to make a solution? How about
three spoons? Five spoons?
8
How can we find out what might happen if you keep
adding salt to 50 ml of water?
9
Write our question in your journal How much
salt can be dissolved in 50 ml of water?
10
Remember you can only change one variable at a
time.What variables should remain
constant?What variable can we manipulate to
answer our question?
11
Discuss with your partner a plan or procedures
for finding out then write it in your journal
(yes, both of you).
12
Write a prediction in your journal telling how
much salt you think can dissolve in 50 ml of
water. Make sure it is a complete sentence.
13
Procedures for saturating a solution

• Use a syringe to put 50 ml of water into the
  bottle.
• Draw a line at the waters level and put tape on
  top of the line.
• Add one level spoon through the funnel into the
  bottle and shake until the salt is dissolved.
• Keep adding spoons of salt until it will not
  dissolved anymore.
• Record your process as you go.

14
What happened to the salt you put in the
water?Where is the salt now?What happened to
the level of the liquid (water)?Why did it go
up?
Answer
Answer
Answer
Answer
15
A salt solution is made of two parts the water
and the salt. These two parts of a solution are
called the solvent and the solute. The solvent
is the liquid into which the solid material goes.
The solute is the material that dissolves. A
solution is always made of a solvent with some
kind of solute dissolved in it.
16
You made a solution by dissolving solid material
in a liquid. In this case the solution was salt
dissolved in water. When solid material is added
to a solution until no more will dissolve, the
solution is a saturated solution. You all made
saturated salt solutions.
17
How do we know we have a saturated solution?How
much salt did it take to saturate 50 ml of water?
Answer
Answer
18
What we really need to know is, how many grams
of salt does it take to saturate 50 ml of water?
In other words, how many grams of salt are
dissolved in your saturated salt solution?Write
this question in your journal.
19
Discuss with your partner a plan or procedures
for finding out, then write it in your journal
(yes, both of you).

• As you discuss, think about
• Is the undissolved salt at the bottom of the
  bottle part of the saturated solution?
• What is the mass of 50 ml of water?

20
Procedures for measuring the solute in a
saturated solution

• Place a cup under the funnel.
• Filter the solution using a WET paper filter. The
  saturated solution will pass through the filter
  the undissolved salt wont.
• Place the saturated solution on one side of the
  balance and 50 ml plain water on the other side.
• Add gram/mass pieces to the plain water to
  achieve balance. The amount of mass added to the
  water is equal to the mass of salt dissolved in
  the saturated salt solution.
• Record the number of grams of salt it takes to
  saturate 50 ml of water

21
Do you think all solutions have the same
saturation point?
22
Because so many things dissolve in WATER, it is
sometimes called the UNIVERSAL SOLVENT.
Remembering that WATER is the UNIVERSAL SOLVENT
might help you remember that the solvent is the
liquid part of the solution into which the solute
dissolves.
23
Kim wrote in her journal, A solution is not a
mixture, it is just a solution. Is she
confused? How would you explain mixtures and
solutions to Kim?
24
INVESTIGATION II,PART 2Citric Acid Saturation
25
Do you think all solutions have the same
saturation point? What was the point of
saturation for the salt-water solution?
ANSWER
ANSWER
26
In this investigation we will use citric acid as
a solute. Do you think that it will have the
same saturation point as the salt-water solution?
Write your prediction in your journal.
27
We will use the same procedures as the saturated
salt-water solution.Prepare a two column chart
in your journal to record your results as you go.
28
Procedures for saturating a solution

• Use a syringe to put 50 ml of water into the
  bottle.
• Draw a line at the waters level and put tape on
  top of the line.
• Add one level spoon through the funnel into the
  bottle and shake until the salt is dissolved.
• Keep adding spoons of salt until it will not
  dissolved anymore.
• Record your process as you go.

29
What similarities and differences did you notice
between salt and citric acid as solutes?
30
Procedures for measuring the solute in a
saturated solution

• Place a cup under the funnel.
• Filter the solution using a WET paper filter. The
  saturated solution will pass through the filter
  the undissolved salt wont.
• Place the saturated solution on one side of the
  balance and 50 ml plain water on the other side.
• Add gram weights to the plain water to achieve
  balance. The amount of mass added to the water
  is equal to the mass of salt dissolved in the
  saturated salt solution.
• Record the number of grams of salt it takes to
  saturate 50 ml of water

31
Were you able to dissolve more salt or citric
acid in the water
32
Jasmine and Mack were making instant iced tea. In
the 1/2-liter glasses, Mack put two spoonfuls of
iced-tea powder and Jasmine put four spoonfuls.
Both filled their glasses half full with water
from the tap. Mack stirred his mixture and it all
dissolved. Jasmine stirred hers, and it didnt
all dissolve.I think you have a saturated
solution, said Mack. Why dont you add more
water?I know another way to make it
dissolve, said Jasmine.Would Macks suggestion
to add more water work? Explain your
answer.What could Jasmine do to make the powder
dissolve?
33
INVESTIGATION II,PART 3The Saturation PuzzleA
performance assessment
34
Working with your partner and following the
procedures previously used in this investigation
find out what the mystery solution is.
35
Can you identify the mystery chemical?Here is a
table of properties for five chemicals. Which
one is the mystery chemical?
36
MIXTURES SOLUTIONS WORD BANKMIXTURE - two
or more materials stirred (mixed)
together.PROPERTY- a characteristic of an
object, something you can observe such as size,
color, shape, texture, temperature, etc.SOLUTION
- a special mixture formed when a material
dissolves in water.DISSOLVING - the process in
which one material disperses uniformly into
another material, so that the first material
seems to disappear.SOLUTE is the solid
material that dissolves into a liquid
(solvent.)SOLVENT is the liquid material that
will dissolve a solid (solute.)SATURATED
SOLUTION when a solute dissolves in a solvent
until no more will dissolve.PRECIPITATE a
solid material that forms as a product of a
chemical reaction.CHEMICAL REACTION - takes
place when two or more materials (chemicals) are
mixed together and a change occurs.REACTANT
chemicals that react when they are mixed.
37
The salt hasnt disappeared it is still there
even though we cant see it because it has
dissolved
38
The salt dissolved.
39
In solution.
40
The level went up.
41
We added salt to the bottle. The salt had to go
some place because it is matter and therefore
takes up space. When it went into the water, it
took up space, raising the level of the liquid.
42
There is undissolved salt on the bottom of the
bottle.
43
Many of you may have recorded the number of
spoonfuls of salt you added to the water, but
this is not a precise way to determine how much
salt is actually dissolved in the solution.
44
Measure its mass.Place an empty cup on the
balance scale.Place a cup with 50 ml of water
on the other side of the balance scale.Add gram
pieces until the scale balances.
45
No, different solutions have different saturation
points.
46
Approximately 13g of salt will saturate 50 mL of
water.
47
You were able to dissolve more citric acid
because it is more soluble than salt in water.