Aim:
i) To find the relationship between supplied energy and change in temperature of water.
ii) To find the specific heat capacity (SHC) of water.
Hypothesis:
As time increases so does the temperature since the water is exposed to the heated
wire for a longer period of time.
Variables:
The Dependent Variable is the temperature of the water, and since the Energy is calculated using temperature it is a dependent variable as well. The constant variables are the voltage and current.
Theory:
Energy Supplied by Heater = Energy Received by Water
Materials:
200ml beaker Connecting Wires Thermometer
200ml water Voltmeter Electronic scale
NiCr-Wire Ampmeter DC Power Supply
Crocodile Clips Stopwatch
Instructions:
i) Assemble the apparatus as shown in the diagram. You need to build your immersion heater by winding the NiCr-wire around a pencil say 8 to 10 times.
ii) Take first measurements of the water incl. its mass and its initial temperature.
iii) Place the immersion heater into the water and turn on the power supply. Adjust the voltage across the immersion heater around 12 to 15 volts.
iv) Measure and record time, voltage, current and temperature at regular intervals in a suitable table (include uncertainties)
v) Draw a suitable graph that will allow you to find the specific heat capacity of the water.
vi) Compare your findings with accepted values for water.
The Essay on Thermal Pollution Water Temperature Oxygen
What is thermal pollution? One of the most serious ways that humans change the temperature of waters is through thermal pollution. The raising of the air or water temperature by artificial means is called thermal pollution. Thermally polluted water often undergoes biological changes that make it less valuable for drinking, recreational, habitat and industrial uses. What causes Thermal pollution? o ...
Observations:
One can observe the process of diffusion and the water changes its color, from clear to a yellowish solution. On one of the poles Nickel starts to accumulate (Electrolysis).
Results:
Mass of Beaker = 205,23 g (0.205 kg)
Mass of Beaker + Water = 391,41 g (0.391 kg)
Mass of Water = 186,18 g (0.186 kg)
Specific Heat Capacity of Water (15˚C) = 4186 J/kgC˚
V (v)
I (amps) t (s) T (˚C) ∆T (˚C) ∆T / T
voltage current time Temperature (change in temp.) Relative uncertainty of Temperature
±0,05 ±0,005 ± 2,00 ± 0,5
13,43 1,42 0 20 0 0,25
13,43 1,42 120 22,3 2,3 0,022
13,43 1,42 240 24,5 4,5 0,020
13,43 1,42 360 27,2 7,2 0,018
13,43 1,42 480 30,1 10,1 0,017
13,43 1,42 600 33,7 13,7 0,015
13,43 1,42 720 35,8 15,8 0,014
13,43 1,42 840 37,9 17,9 0,013
13,43 1,42 960 39,1 19,1 0,013
13,43 1,42 1080 42,2 22,2 0,011
13,43 1,42 1320 43,8 23,8 0,011
13,43 1,42 1440 45 25 0,011
13,43 1,42 1560 46 26 0,011
13,43 1,42 1680 47,1 27,1 0,011
13,43 1,42 1800 48,1 28,1 0,010
13,43 1,42 1920 49 29 0,010
∆V / V ∆I / I ∆t / t ∆E / E ∆E
Relative uncertainty of Voltage Relative uncertainty of Current Relative uncertainty of time Rel. uncertainty of Energy
= (∆V / V)+( ∆I / I)+( ∆t / t) Absolute uncertainty of Energy
= E*(∆E / E)
0,000372 0,00352 0 0 0
0,000372 0,00352 0,01667 0,020560 47,1
0,000372 0,00352 0,00833 0,012227 56,0
0,000372 0,00352 0,00556 0,009449 64,9
0,000372 0,00352 0,00417 0,008060 73,8
0,000372 0,00352 0,00333 0,007227 82,7
0,000372 0,00352 0,00278 0,006671 91,6
0,000372 0,00352 0,00238 0,006274 100,5
0,000372 0,00352 0,00208 0,005977 109,4
0,000372 0,00352 0,00185 0,005745 118,3
0,000372 0,00352 0,00152 0,005409 136,2
0,000372 0,00352 0,00139 0,005282 145,1
0,000372 0,00352 0,00128 0,005175 154,0
0,000372 0,00352 0,00119 0,005084 162,9
0,000372 0,00352 0,00111 0,005005 171,8
0,000372 0,00352 0,00104 0,004935 180,7
E (J) Ew (J) m*∆T c
= V*I*t
The Essay on Ant Acid Water Beaker Base
TJ Gentile Bio lab 11/18/2003 Mrs. Trunfio Experiment 3: Acids and Bases Hypothesis: My Hypothesis is that Aspirin would be the Best buffer because it has a strong acid content and it May be able to withstand changes better. Materials Needed: -CBL System -TI Graphing Calculator -Venire pH System -Venire DIN adapter Cable -250- mL beaker -Various Biological Organisms -Various Non Biological ...
Electrical Energy Supplied = m*c*∆T
Energy received by water Specific heat capacity
0 0 0
2288 2288,472 0,428214 5344,225084
4577 4576,944 0,83781 5462,985641
6865 6865,416 1,340496 5121,549039
9154 9153,888 1,880418 4868,007007
11442 11442,36 2,550666 4486,028355
13731 13730,832 2,941644 4667,740896
16019 16019,304 3,332622 4806,816975
18308 18307,776 3,556038 5148,363431
20596 20596,248 4,133196 4983,128794
25173 25173,192 4,431084 5681,045992
27462 27461,664 4,6545 5900,024492
29750 29750,136 4,84068 6145,858846
32039 32038,608 5,045478 6349,96486
34327 34327,08 5,231658 6561,415138
36616 36615,552 5,39922 6781,637348
Evaluation and Analysis:
The obtained results support the theory since, according to the results, the Energy received by the water was exactly the same as the Energy supplied.
The points on the Graph drawn show a pretty big fluctuation due to inaccuracy and uncertainties. There was also a small energy loss in the system due to Electrolysis. This happened because we used tap water, which has free floating ions, allowing the Nickel from the wire to form at one of the crocodile clips.
The heater (in this case a NiCr-Wire Immersion Heater) was touching the sides and the bottom of the beaker, meaning that it emits some of the heat towards the sides of the beaker instead of the water. This was probably our biggest source of error in the experiment. The thermometer was also touching the bottom of the beaker for half of the experiment, meaning that it measured the temperature of the beaker instead of the water. We overcome this by placing the thermometer into a rubber bung so that the thermometer would float in the water and not touch the beaker.
Another Source of Error was that we did not record all the readings from the volt- and ammeter for every reading of temperature. Human Error played another major role in inaccuracies. Instead of using a 200mL Beaker we used a 600mL Beaker, this means that the water had a larger surface area allowing it to cool off more easily…
There are many things we could have done to improve this experiment. First, we should have kept the thermometer in the middle of the beaker (but away from the wire heater) and not touching the beaker. Second, we should have recorded all the readings from the voltmeter and ammeter to keep the absolute uncertainties more accurate.
The Essay on Dialysis Bag Glucose Beaker Water
Diffusion LabProblemWill starch, water, glucose, iodine or a combination of the above diffuse across the membrane of the dialysis bag causing the bag to either expand or shrivel? Hypothesis & Strategy I believe that the smaller molecules, such as glucose and water will diffuse through the dialysis bag's membrane causing it to expand, due to the concentration gradient. I would test this ...
In other words this experiment was a success with exception to the uncertainties and errors made.
Conclusion:
The Hypothesis has been proven by this experiment and so was the stated Theory, but not with 100% accuracy since the experiment had a lot of flaws, which could have easily been avoided. The Results might look identical which would prove the theory but due to the rounding off one could not see the slight fluctuations between the answers after at least 5 decimal places.
