Costanzo-Kibria
10A
12-20-12
Problem Statement:
Determine the effect of copper (II) Sulfate particle size, temperature of water mixing
method on the rate of dissolution.
Hypothesis:
The copper (II) sulfate will have a higher dissolution rate when the smaller particles are
put into the higher temperature with the faster mixing method.
Materials:
0-3°C water, H20
22-28°C water, H20
55-60°C water, H20
Copper (II) Sulfate, CuSO4 * 5H2O, fine
crystal
Copper (II) Sulfate, CuSO4 *5H2O, powder
Copper (II) Sulfate, CuSO4 *5H2O, medium
crystal
Scale, 0.01g precision
Thermometer probe, 0.01°C precision
Hot Mit
10 mL graduated cylinder
100 mL beaker
(3) Test tubes, large
Test tube stopper
(14) Weight boat
Test tube rack
Stop Watch
Hotplate
TI-Npsire Calculator Randomize Function
Procedure:
Safety Note:
*Copper (II) sulfate is moderately toxic; avoid contact with skin and eyes.
Set up:
1. Start hot plate on a setting of 2-3 and gently warm 200 mL of water to 55-60°C. Solution
should never boil.
2. 5°C and 22-28°C solutions have already been prepared and are located in the cooler and on
the demo table.
3. A clean dry test tube will be used before each experiment.
4. Have stop watch ready.
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Costanzo-Kibria
10A
12-20-12
Protocol:
1. Randomize trials using the random integer function with the TI-Nspire calculate function.
2. Mass out 0.2 grams of the copper (II) sulfate in the specific particle size of the trial using a
weigh boat
3. Using a 10 mL graduated cylinder, measure out 10 mL of water specific to your trial.
4. Pour the water into a dry test tube and pour the copper (II) sulfate into the test tube.
5. Plug the test tube with a stopper and start stop watch.
6. Agitate solution according to the trials mixing method.
7. Record data in the data tables in seconds that the solution took to dissolve.
8. Repeat steps 1-7 for the rest of the trials.
Diagram:
Fine Crystal (Standard)
Medium Crystal (+)
Powder (-)
Figure 1. Particle Sizes
Figure 1 above shows the crystals used for the experiment. The powder on the left is the
low value. The fine crystal in the middle is the standard. The medium crystal on the right is the
high value.
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10A
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Data and Observations:
Table 1
Factors Used in Experiment
Factors
(+) Values
Standards
Extent of mixing (sec)
1/s
5/10s
Temperature (°C)
55-60
medium
crystal
22-28
fine
crystal
Particle Size
Table 2
Data Collected During the Random Trials
Temperature
Trials
Particle Size
(°C)
1 Standard
3 +
+
8 +
+
7 +
4 +
6 Standard
9 +
10 +
5 2 11 Standard
(-)
Values
1/10s
0-3
powder
Mixing Method
+
+
+
+
-
Results in Time of
Dissolution (s)
87
180
300+
189
300+
87
17
70
42
203
64
In Table 1, the factors used for the experiment are shown. The highs, lows, and
standards are shown in the table. The factors that will be used are the extent of mixing, the
temperature of the water, and the particle size of the copper (II) sulfate. Table 2 above shows
the data collected during the trials. The trials were randomized on a TiNspire CX calculator.
Trials 1, 6, and 11 are the standards.
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Costanzo-Kibria
10A
12-20-12
Table 3
Observations
Trial
Day 1 12/7/12
1
3
2
4
5
6
Day 2 12/10/12
7
8
9
10
11
Observations
Redid the second day and Alex flicked. Time made more sense.
Alex flicked.+,+,+ light blue
Alex flicked. -,-,- light blue took longer with cold water
Alex flicked. +,-,- Greater than 5 minutes and doesn’t dissolve very
well.
Alex flicked. Some copper stuck to side of tube. -,-,+
Standard. Alex flicked.
Alex flicked +,-,+ took longer with cold water
Alex flicked+,+,- took longer than 5 min
Alex flicked -,+,+ Alex flicked and it went really fast like we
hypothesized
Alex flicked -,+,- took just a little longer than previous trial
Alex flicked standard about right with the other S
Table 3 above shows the observations made during the experiment. The same
researcher mixed the solution every time so that there would be no effects of different
methods. Notice also that there were two trials that took longer than 5 minutes to dissolve.
This is believed to be because of the cold water and the medium size crystal. Also in trial 5 there
was some powder that stuck to the side of the tube and did not get into the solution as fast as
the rest so that may be why it took a little longer for it to dissolve.
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Costanzo-Kibria
10A
12-20-12
Data Analysis and Interpretation:
Table 4
Effect of Particle Size
(-) Values:
(+) Values:
17
180
70
300
42
189
203
300
Average=83 Average=242.25
Figure 2. Effect of Particle Size
In Figure 2 and Table 4 above, the effect of the particle size is shown. On average, as the
particle size increased, the dissolution rate increased by 159.25 seconds.
Table 5
Effect of Temperature (C)
(-) Values
(+) Values
189
180
300
300
42
17
203
70
Average=183.5 Average=141.75
Figure 3. Effect of Temperature (C)
In Figure 2 and Table 5 above, the effect of the temperature of the water is shown. On
average, as the temperature increased, the dissolution time decreased by about 41.75 seconds.
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Costanzo-Kibria
10A
12-20-12
Table 6
Effect of Mixing Method
(-) Values
300
300
70
203
Average=218.25
(+) Values
180
189
17
42
Average=107
Figure 4. Effect of Mixing Method
Figure 4 and Table 6 above show the effect of the mixing method used. On average, as
the mixing method increased, the dissolution time decreased by 111.25 seconds.
Interaction Effect of Particle Size and
Temperature
300
Dissolution (sec)
250
P(+)
Table 7
Interaction Effect of Particle Size and Temperature
200
T(-)
150
100
50
P (-)
0
-1
1
P(+)
(solid)
P(-)
(dotted)
T(+)
244.5
240
122.5
43.5
Tem perature (ºC)
Figure 5. Interaction Effect of Particle Size and Temperature
Figure 5 and Table 7 above, shows the interaction effect of the particle size and the
temperature. The lines are not parallel which means there was an interaction. When calculated
the interaction effect came out to 37.25 seconds.
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Costanzo-Kibria
10A
12-20-12
Interaction Effect of Partcle Size and Mixing Method
350
Dissolution (sec)
300
Table 8
Interaction Effect of Particle Size and Mixing Method
250
200
P (+)
150
M(-)
100
50
P (-)
0
-1
1
Mixing Method
P(+) (solid)
P(-)
(dotted)
M(+)
300
184.5
136.5
29.5
Figure 6. Interaction Effect of Particle Size and Mixing Method
In Figure 6 and Table 8 above, the interaction effect of the particle size and the mixing
method is shown. The lines look almost parallel, indicating that there is a small interaction of
these factors. The interaction effect was -4.25 seconds, which is smaller than the rest of the
effects.
Interaction Effect of Temperature (ºC) and
Mixing Method
300
Dissolution (sec)
250
200
150
T (-)
100
Table 9
Interaction Effect of the Temperature and Mixing Method
T (+)
M(-)
50
0
-1
1
Mixing Method
T(+)
(solid)
T(-)
(dotted)
M(+)
185
98.5
251.5
115.5
Figure 7. Interaction Effect of the Temperature and Mixing Method
In Figure 7 and Table 9 above, the interaction effect of the temperature and the mixing
method is shown. These lines are not parallel indicating an effect. This effect is 24.75 seconds.
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Costanzo-Kibria
10A
12-20-12
Standards
Dissolution (sec)
100
80
60
40
20
0
0
1
2
3
4
Trial
Figure 8. Standards
There were three standard trials taken during the experiment. Figure 8 shows them on a
graph to show how close they are. The first two were the same and the third was smaller. This
may be because of an error or something was done differently during this trial.
-111.25
M
-41.75
T
-4.25
PM
0
24.75
TM
37.25
PT
159.25
P
Figure 9. Dot Plot of Effects
The figure above shows the dot plot of the six effect variables. The two effects farthest
from zero will most likely be significant, but this cannot be known for sure without doing a test
of significance. To find if a variable is significant, take the absolute value of the effect. If this is
greater than or equal to two times the range of standards it is significant. The range of
standards for this experiment is 23. When this is multiplied by two it becomes 46. Now it is
seen that anything greater than or equal to 46 will be significant. The only variables that are
significant for this data is the particle size and the mixing method.
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Costanzo-Kibria
10A
12-20-12
Y= 162.625 + (159.25/2)P + (-111.25/2)M + NOISE
Figure 10. Parsimonious Equation
Figure 10 shows the parsimonious equation that only includes the vital few that were
selected by the test of significance. The two variables are the particle size and the mixing
method. Then the grand average is also added onto the equation. The grand average does not
include the standards, just the trials. The noise on the end of the equation is any other factor
that could affect the variables.
Check:
+,+,+:
Y= 162.625 + (159.25/2)(+1) + (-111.25/2)(+1) + NOISE
= 186.625
Figure 11. Check of the Parsimonious Equation
The parsimonious does work. As seen in Figure 11, when the highs are plugged into the
equation is gives 186.625 as the answer. When the data that was collected is compared to the
check it seems that it does work, even though the number is not exact. This is because there is
no third variable, just the two that were significant.
Conclusion:
The data gathered from the experiment shows that the powdered form of Copper (II)
Sulfate in 55-60°C of water being mixed once every second gave the fastest result of
dissolution, which was 17 seconds. Since this is the case, the hypothesis made by the
researchers is accepted. This scenario of water temperature, mixing method, and particle size
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Costanzo-Kibria
10A
12-20-12
had the fastest rate of dissolution for many reasons. One of the reasons is the speed of the
mixing method. The solute was being agitated once every second causing the particles to
spread in the water. The copper (II) sulfate particles bonded more quickly with water molecules
because the water is polar and the copper is ionic which caused attraction between the copper
and water. With the fast mixing method, the particles bonded with each other more quickly
causing a quicker dissolution. Also, another reason is the high water temperature. The heat of
the water is given off by the actual speed of the particles in the water, so the higher the
temperature of water, the faster the particles move. The fast moving particles in the water
spread and attracted many more copper (II) sulfate molecules in a faster time. The kinetic
molecular theory states that with higher temperature, there is higher kinetic energy. This
higher kinetic energy causes faster collisions of molecules and overall a faster dissolution time.
This also means that cooler water has slower kinetic energy causing an overall slower
dissolution time. This comparison can be seen in trials 9 and 5 of the experiment. They both
have the same mixing method and particle size, but one has 55-60°C water while the other has
0-3°C water. Trial 9 had the higher water temperature and also higher dissolution rate of 17
seconds. Trial 5 had the lower temperature and a dissolution rate of 43 seconds. Finally, a big
impact on the rate of dissolution was the particle size. The low particle size (powder) had rates
of dissolution which were all faster than the trials with the high particle size (medium crystal).
This may have occurred because of the closeness of the particles and also the size of these
particles. The medium crystals had bigger particle size and were also packed closely together,
so the water molecules had to break down the copper (II) sulfate molecule, starting at the
surface. Since the size of the particle was bigger, the water molecules took longer to break it
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Costanzo-Kibria
10A
12-20-12
down. To completely dissolve the medium crystal, the water molecules had to break down each
layer of copper (II) sulfate particles from the surface all the way to the center which caused the
rate of dissolution to be slow. On the other hand, the powder had a very high rate of
dissolution. The reason for this can be associated to the same reasoning for the medium
crystals, surface model. The powdered copper (II) sulfate has smaller particles and the water
can break it down to its center much quicker. Even though the medium crystal and the powder
had the same mass, the breaking down of the particles were different because of the face that
the powder was smaller and easier to break down. All of this scientific fact supports the
experimental evidence in saying that the high temperature with 1 per second mixing method
on powdered copper (II) sulfate has the highest rate of dissolution.
Even though the science proves the experiments outcome, there were still a few
weaknesses. One of the weaknesses was keeping a uniform method of mixing. The mixing was
done by flicking the test tube in which the solution was in, but one flick may be harder then the
next one or the one before it. Another weakness was keeping the test tube still so that no other
shaking caused the solution to dissolve than the intended means of mixing.
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