Experiment 1
Fundamental Laboratory Techniques

POSTLAB QUESTIONS

1.

A) Use the experimental data given below to calculate the density of water for a 100 mL graduated cylinder and for a 10.00 mL volumetric pipette. Calculate the average density and the range of densities for the graduated cylinder and the pipette.

mass of empty beaker: 24.342 g

 

Graduated cylinder:

trial number	mass of beaker + water	volume of water
#1	35.936 g	11.2 mL
#2	35.050 g	10.5 mL
#3	35.111 g	11.0 mL

10 mL pipette:

trial number	mass of beaker + water	volume of water
#1	34.360 g	10.00 mL
#2	34.349 g	10.00 mL
#3	34.343 g	10.00 mL

B) If the true (theoretical) density of water at this temperature is 0.99993 g/mL, comment on the accuracy and precision of the graduated cylinder compared to the 10 mL pipette.

2. One electronic balance in the lab was used to make this mass reading: 18.52 g. What is wrong with this mass reading?

3. The following mass measurements were made: 0.123 g, 0.265 g, 0.101 g, 0.532 g. The true mass of the object is 0.259 g. Discuss the accuracy and precision of the balance