The meaning of this experiment was to understand and use the basic tools for chemistry. During this experiment, many calculations were taken from data collected. We had to make sure measurements were taken accurately in order to complete the right equations. Using these equations we could determine volume, weight, and masses of specific objects. Also, we were introduced to utilities found in every laboratory. These were used help find the mass and temperatures of objects. The MeasureNet was used to help us graph out data and take temperatures while we used different balances to record masses of objects.
The procedure followed was that given in the Lab booklet
Data and Results:
The data has been organized by using different tables and graphs. Multiple trials were performed in order to determine accuracy. Refer to the report sheets for data information. All graphs and tables are included also.
A.) The graph of Water Temperature vs. Time was included.
B.) Graphs that were used have been given for the experiments and also the lab
report sheets summarize the experimental results that were recorded in the
Glassware Used Expected Actual Volume
Beaker 50 ml 51.062mL
Graduated Cylinder 50ml 48.841mL Trial2
Pipet 10ml 9.809mL 9.804mL
Buret 10ml 10.064mL 10.060mL
Accuracy is defined as the quality or state of being accurate or exact when recording measurements in the experiments. Precision is being precise in a measurement or an operation of the experimental state.
In the mass measurements part of the lab we learned how to use the scale and found that these scales are very exact. They had very miniscule difference between the trials and between the measured and calculated masses of the crucible parts.
On the Water Temperature vs. Time graph the temperature increases abruptly when heat is applied to the water causing it to boil. When it reaches boiling point heat was taken away and the temperature decreases slowly and the graph ends at 900 seconds.
Through the experiments we learned that the beaker is the most unreliable tool to use. Although it measures to a certain point the wide diameter could cause the results to be inaccurate, therefore throwing off the equations and corrupting the experiment. The graduated cylinder is the next least accurate. It holds many of the problems that the beaker has like the diameter and lack of precision. The two most precise instruments would be the pipet and buret since their diameter is small and it records closer to the actual measurement.
1. A.) In the experiment the temperature rises drastically in the first 250 seconds.
Then it stays flat till about 250 seconds and then slowly decreases.
B.) The temperature increases as the water of the heat starts to hit the boiling
point. The boiling point of this part of the experiment is 100 degrees
Celsius. The temperature then decreases to it normal state.
2. The sensitivity the balance can detect is 0.0001g.
3. The largest difference between two of my measurements using the analytical scale was .0008.
4. The error statement we found for the beaker was 4.91mL. The graduated cylinder was .027ml. The pipet was .01 ml and the buret was 2.164mL.
5. Using the Histograms from the class we came to the assumption that the buret is the most accurate tool for measurement. The class results for the buret was 10.007 mL. The second most accurate tool was the pipet and its volume is9.883 mL. The cylinder followed next with a 49.352 volume. The least accurate was the beaker, its volume was 46.785 mL and this was caused by the wide diameter. The relative error of the beaker was 2.08%, while the error for the cylinder was 2..37%. The error for the pipet was .19% for both trials and the burets errors were 0.63% and 0.60% according to the results.
6. A.) The standard deviation shows us that the beaker was least accurate with a 1.758 error. The cylinder had a 0.680 error and was second least accurate, but was more precise than the beaker because studying the Histograms results shows us that the error was present for the rest of the class. The reason for this would be from the wide diameter of the beaker.
B.)The buret and pipet were the closest in standard deviation. The buret had a 0.144 error while the pipet had a .120 error. This shows how accurate the pipet was during the experimentation. If procedures were accurately taken using the pipet then measurements would be more precise than the buret. One of the problems the pipet had was using the pipet pump. The pump made it difficult to draw water out of the beaker and this could affect the results of the experiment.
7. This would affect the results of the experiment because carbon tetrachloride
could be a thicker substance and would be hard to use the pipet with since the
diameter of the pipet is so small.
8. A.) A buret would be most accurate for measuring ten mL of a liquid with a
B.) A graduated cylinder would be most accurate for measuring fifty mL liquid with a .5% accuracy.
C.) A beaker would be most accurate for measuring several twenty mL samples of a liquid with a precision of 10%.
In this lab we were able to achieve most of our goals. The goals were to learn how to use the equipment and to see what devices are the most accurate for measurement of volume and mass. The errors in this lab seem to pop up everywhere. The first was that the measure net system did not work to find temperature for the probe calibration. The next was that 1 of the analytical balances would not rezero. Most of the errors dealing with finding volume came from human error by not taking the correct measurements. These thing contributed to the error and standard deviation in this
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