INVESTIGATION:
When copper sulfate is mixed with sodium hydroxide a
solid precipitate called copper hydroxide will form.
Danielle wants to know if the amount of copper sulfate in
the beginning will effect the amount of precipitate that
forms after the reaction.
hypothesis: If you increase the concentration of the 1.
IV: _________________________________
2.
DV: ________________________________
3. Identify 2 factors in the investigation that should be
held constant throughout the investigation.
copper sulfate, then more precipitate will form.
1,
PROCEDURE:
Danielle mixes different concentrations of copper sulfate
solution with sodium hydroxide solution. In all test tubes,
she mixes together 30 mL of each solution.
After the reaction, she used a filter
to collect the copper hydroxide (solid
product/precipitate) that formed and
set it out to dry.
Copper
hydroxide
(solid
precipitate)
Copper
hydroxide
(solid
precipitate)
2.
4. Danielle made sure that there was only 1 variable
different in the experiment. Explain why it was
important to keep the factors in question #3 above
the same and have only one variable different ?
After the precipitate dried, she
scraped the copper hydroxide
off the filter and measured the
mass produced and recorded it
in the table. She did 3 trials
each concentration.
9. Use the data from the table to
construct a LINE graph.
Graph only the averages for
mass of copper hydroxide.
3.0 -
CHECKLIST............
Title
Effect of IV on DV
IV labeled and unit
2.0 -
DV labeled and unit
Appropriate scale on x-axis
Appropriate scale on y-axis
data correctly plotted and
connected
1.0 -
0.2 0 -I
0
I
.1
I
I
1
DATA:
Concentration
of
Copper Sulfate
(Molar)
Trial
1
Trial
2
Trial
3
Average
Mass of Copper
Hydroxide
(g)
0.8 molar
2.6 g
2.5 g
2.7 g
2.6 g
0.5 molar
0.9 g
1.8 g
1.6 g
1.7 g
0.1 molar
0.6 g
0.5 g
0.7 g
5. Calculate the average that belongs
in the empty box of the data table.
calculation
6. Explain why conducting 3 trials instead of one will help
Danielle reach a more reliable conclusion.
7. What scientific tool did Danielle
use in order to collect her DATA?
8. Describe one possible reason why one mass of copper
hydroxide from the 0.5 molar concentration is so
different than the other masses with the same molar
concentration.
10.
12. FURTHER INVESTIGATION
CONCLUSION:
When the concentration of the copper sulfate was
increased. the amount of solid precipitate (copper
hydroxide) that was produced
(increases, decreases)
EVIDENCE TO SUPPORT YOUR CONCLUSION
Danielle thought other factors, besides the
concentration of copper sulfate, may also affect the
mass of precipitate produced.
Write another testable question that Danielle could
use to test how a different factor affects the
mass of precipitate produced.
(Does
11. PREDICT: (use the graph)
Predict the the mass of precipitate
produced if the concentration of
copper sulfate is 1.0 molar.
(number and unit)
Predict the the mass of precipitate
produced if the concentration of
copper sulfate is 0.3 molar.
(number and unit)
PROOF
extend graph
with DOTTED
line
?affect amount of precipitate produced?)
13. HYPOTHESIS:
Write a hypothesis for this new investigation in #12.
(If......, then......)
Name
THE
DATA
ANALYZE THE DATA
AND MAKE A
CONCLUSION
#7
PE itate
cip
Pre
IDENTIFY THE
VARIABLES
Sodium
Hydroxide
Solution
30 ml
0.1 molar
Copper
Sulfate
Solution
30 ml
Sodium
Hydroxide
Solution
30 ml
30 ml
0.5 molar
Copper
Sulfate
Solution
30 ml
30 ml
Sodium
Hydroxide
Solution
GRAPH
THE
DATA
ACTUAL DATA
https://chemicalparadigms.wikispaces.com/
Group+3
0.8 molar
Copper
Sulfate
Solution