Name: Date Performed:
Date Submitted:
Report Sheet No. 2
Changes in Matter
I. Objective:
Identify the difference between physical and chemical
changes in matter.
II. Materials:
6 test tubes water
3 evaporating dishes sodium
chloride
spatula hydrochloric
acid
tongs magnesium
ribbon
alcohol lamp sulfuric
acid
10 ml graduated cylinder ammonium
chloride
4 250 ml beakers crushed
iced
thermometer evaporated
milk
iron ring and iron stand acetic
acid/ vinegar
wire gauze iron
fillings
dropper
Procedure:
A.
1. In a test tube half-filled
with water, add about a spatula level of sodium chloride. Shake until all the
salt is dissolved. Then transfer the solution into an evaporating dish and heat
until it dries up.
2. In another test tube filled
with 5 mL hydrochloric acid, place a piece of magnesium ribbon. When the metal
has dissolved completely, transfer the liquid into an evaporating dish and heat
until it nearly dries up.
B.
1. Fill with water half of each
of the three test tubes.
2. Into the first test tube,
add 3 mL of concentrated sulfuric acid. Into the second, add a spatula of
sodium chloride. And into the third, add a spatula of ammonium chloride.
3. Feel each test tube with
your palm. Note any thermal change.
C.
1. Fill with crushed ice about
three-fourths of the beaker.
2. Put in the thermometer and
note the lowest temperature registered.
3. Observe if the temperature
remains constant. Continue observing the changes, if there are any, until 2 or
3 minutes after the last ice crystal has disappeared.
D.
1. Boil half a beaker of water.
Record the temperature at which the steam escapes vigorously, and note whether
the temperature remains constant.
2. Hold a dry evaporating dish
2 or 3 cm above the beaker. Record your observation.
E.
1. Put 5 mL of hydrochloric
acid in a test tube. Add a pinch of iron fillings. Observe what happens.
F.
1. Put 10 mL of vinegar in a
test tube. Add liquid milk drop by drop. Observe what happens.
IV. Observations:
A.
B.
C.
D.
E.
F.
V. Questions:
A.
1. Compare the results of
heating (a) water with table salt and (b) combining hydrochloric acid with
magnesium metal.
2. Describe the type of change
undergone by hydrochloric acid and magnesium. Explain your answer.
3. Identify the kind of change
that took place when salt disappeared in water. Give reasons for your answer.
B.
1. Compared the results
obtained in the three test tubes.
C.
1. Is the melting of ice a
physical change? Explain your answer.
2. Did the temperature fluctuate
while the ice was melting?
D.
1. Name two processes undergone
by matter which were observed in the experiment.
2. Describe what you observed
on the evaporating dish.
E.
1. Describe what happens when
iron fillings are added to hydrochloric acid.
2. Is a new substance formed
when you add iron fillings to hydrochloric acid? How do you know?
F.
1. Describe what happens when
milk is added to vinegar.
2. Is a new substance formed?
How do you know?
3. When do we say a chemical
change has occurred?
VI. Conclusion:
