Density and Treatment of Data.pdf - Density and Treatment...

Density and Treatment of Data
Chemistry 1A Spring 2019 February 14, 2019
Objective/abstract
The purpose of this experiment is to understand how to perform statistical analysis of
experimental data. We will determine the density of a solid, calibrate the volume of a
pipette and use the calibrated pipette to determine the density of an unknown liquid.
Theoretical
verage A =
3
x + x + x
1 2 3
ange R = W = x x
(
largest
−
smallest
)
eviation δ x x D =
1
= −
1
verage Deviation δ A = =
3
δ + δ + δ
|
1
| |
2
| |
3
|
tandard Deviation s S = =
√
3−1
δ + δ + δ
2
1
2
2
2
3
ensity D =
m
V
Pre-lab Sections: Experimental Procedure and MSDS Information
Part 1 :Determination Of the density of a metal
(a) Obtain A metal slug and use analytical balance to measure its mass
(b) Fill a 100mL graduated cylinder halfway and record volume to nearest 0.1 mL.
(c) Tie the metal slug with a string and carefully drop it into the 100 mL graduated
cylinder. Avoid splattering.
(d) Repeat the procedure two more times. Use the same mass recorded in step (a)
above.

Part 2: Calibration of pipets
(a) Use the analytical balance to weigh a clean and dry 50 mL Erlenmeyer flask with
a stopper to ± 0.0001 g.
(b) Pipet 10 mL of deionized water into the weighted flask/stopper.
(c) Weighthe Erlenmeyer flask and its contents to ± 0.0001 g.
(d) Using the addition method, repeat this procedure two more times.In the addition
method, we subtract the previous mass reading to obtain the mass of the water for
each trial.
(e) Determine the temperature of the water to ± 0.1 C and look up the density in the
Handbook. Record the density of water and calculate the volume corresponding to
one aliquot of the 10mL pipette.