University Chemistry Lab: Accuracy and Precision of Glassware Report

This report details an experiment assessing the accuracy and precision of various laboratory glassware, including bulb pipettes, graduated pipettes, burettes, and measuring cylinders. The experiment involved measuring 20 mL of water using each apparatus and comparing the results to manufacturer specifications. The analysis included individual and class average results, highlighting deviations and potential sources of error such as parallax errors and faulty recordings. The findings indicated that the bulb pipette offered the best combination of accuracy and precision, while the burette provided a good alternative when a specific accuracy was required. The measuring cylinder showed the lowest levels of both accuracy and precision. The report concludes by recommending the appropriate glassware for applications based on desired levels of accuracy and precision.

Discussion
The two individual experimental results for the Bulb pipette (20.02 and 20.01) were in
the ranges of the manufacturer’s specifications (2 0.00 ±0.06 mL.The results are
comparatively both accurate and have higher precision since the values are closer to each
other. Individual results for Graduated pipette result for the first graduated pipette (20.08)
was out of range of the manufacturer’s specification 2 0.00 ±0.02 mL while the 2nd result was
within range (19.99mL). The average value for the two Graduated pipettes were out of range
of the manufacture’s specification and do not show higher precision as the two values have
higher deviation. Individual Burrete results are relatively not precise as the difference
between the two values is (20.02-19.95=0.07). The results are however comparatively
accurate because the values are within the range of manufacturer’s specifications of (
2 0.00 ±0.08 mL). The two readings obtained from measuring cylinder shows both low levels
of accuracy and precision. The two results are out of manufacturer’s specifications (
2 0.00 ±1 mL ¿ and also shows a wide disparity between the two measured values (17.27-
17.02mL).
The class average values for Bulb Pipette and individual results are within the
manufacturer’s specification although the standard deviation for class average is at 0.09mL.
The graduated pipette reading for the class average and the individual results are both out of
range the manufacturer’s specification with a large standard deviation of 0.17mL. The
average burette readings for both individual readings and class average conforms to
manufacturer’s specifications while measuring cylinder values are out manufacture range in
both cases.
The variations in class average values shown by relatively high standard deviations in
all the measuring equipment can be attributed to possible parallax errors while taking the
readings, possible cases of gross errors in computing the measured data and faulty recordings.
The most appropriate apparatus should be one that offers both precision and accuracy.
From the above discussion, it can be seen that measuring cylinder offers neither. Bulb Pipette
is seen to offer both accuracy and precision compared to all the other apparatus.

Conclusion
From the discussion of the experimental results, it can be seen that in applications
where accuracy and precision are paramount, Bulb Pipette offers the best measuring
apparatus. In application where an accuracy and precision of up to 0.08mL is required,
Burette offers the best alternative while a graduated cylinder is found to be a suitable choice
for precision and accuracy of slightly 0.2mL and measuring cylinder is found to be only a
suitable choice when the desired precision is greater than 2.0mL.