Analysis:
- Density = Mass Density = Mass Density = Mass
Volume Volume Volume
Density = 69.87 Density = 68.15 Density = 71.51
Pie(2.25)( 4.9) pie(2.25)(4.8) pie(2.25)(4.9)
Density = 69.87 Density = 68.15 Density= 71.51
78 78 78
Density = 0.90 Density = 0.87 Density = 0.92
- 0.90 + 0.87 + 0.92 / 3 = 0.89.
The average density using the first method was 0.89
- 20 + 20 + 20 / 3 = 20 C The average temperature of the liquid was 20 C
-
percent error = difference between observed value and accepted value x 100
accepted value
= 0.89 – 0.7854
0.7854
= 0.105
0.7854
= 0.134 x 100
= 13.4 %
- 5. Density = Mass Density = Mass Density = Mass
Volume Volume Volume
Density = 69.87 Density = 68.15 Density= 71.51
79 78 82
Density = 0.88 Density = 0.87 Density = 0.87
- 0.88 + 0.87 + 0.87 = 0.87
The average density using the first method was 0.87 g/Ml
- Percent error = difference between observed value and accepted value x 100
accepted value
= 0.87 – 0.7854
0.7854
= 0.0846
0.7854
= 0.108 x 100
= 10.8 %
Discussion:
By looking at the results, it is shown that the density of the liquid for method 1 was 0.89g. The known density for the liquid at the given temperature was 0.7854g, and the percent of error was 13.4%. As for method 2 the density of the liquid was 0.87g. The known density for the liquid at the given temperature was 0.7854g, and the percent of error was found to be 10.8%. ,
It is clear to see that the graduated cylinder proved to be a more accurate tool for measurement in this lab; thus, completing the purpose of the lab. This statement can be proven by comparing the average value of density for the graduated cylinder (0.87g) and the beaker (0.89g) with the accepted value of 0.7854g. The graduated cylinder was a closer measurement to the true or accepted value than the beaker showed. However, while the graduated cylinder proved to be a more accurate tool in measuring liquid amounts, the beaker is found to be more precise. This is shown in the table above with the significant digits in the measurement. While the mass of the beaker and liquid in trial 1 was 120.73 g, and the volume of liquid measured with the graduated cylinder in trial 1 had only 2 significant digits which was 79.
Possible sources of error for the first method are not measuring the proper amount of liquid in the beaker, errors in the math calculations. Not measuring the correct amount of liquid in the beaker causes problems because it would not be very close to the other times the test was done, creating an inaccurate average. Miscalculating the math is a large problem because it can cause all the rest of the calculations needed for percent error, and the calculations that are dependant accurate answers. Spilling water is another big problem because the same amount of water is needed for both methods for them to be accurate. Possible source for error in the second method are the same as the first method. The same things can go wrong, because calculations are being made, measurements are being taken, and liquid is being transferred from beakers to the graduated cylinder.
The better method is the second method (graduated cylinder). This is due to the second method being accurate as opposed to being solely precise like the first method (beaker). It was found to be a more accurate method because it had 2.6% less of a percent error than method 1. It is said that without a high degree of precision, a problem may go undetected and uncorrected, thereby affecting the overall accuracy. Therefore it can be concluded that the second method also had some level or precision in order for it to have been accurate.
Conclusion:
In conclusion, it has been determined by looking at the data that the graduated cylinder is a more accurate method of measuring liquid amounts. The reason for this is that the graduated cylinder’s average density was 0.87g where as the beaker’s average was 0.89g, by comparing the two to the accepted value of 0.7854g, conclusions can be drawn. It can be concluded that the graduated cylinder was closer to the accepted value than the beaker was. The percentage error for the beaker was found to be 13.4 %, and the graduated cylinder percentage error was 10.8%. With this statement, it accomplishes the purpose of the lab, which was to find which of the two tools were more accurate and precise.