Calculations

Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation.

1. Part I: Density of Unknown Liquid

1. Calculate the mass of the liquid for each trial. (Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder with liquid.)

Trial 1

36 - 25.5 = 10.5

Trial 2

36.5 - 25.5 = 11

Trial 3

36.9 - 25.5 = 11.4

2. Calculate the density of the unknown liquid for each trial. (Divide the mass of the liquid calculated above by the volume of the liquid.)

Trial 1:

10.5 / 8.7 = 1.21

Trial 2:

11 / 8.5 = 1.29

Trial 3:

11.4 / 8.8 = 1.30

2. Part II: Density of Irregular-Shaped Solid

1. Calculate the volume of the irregular-shaped solid for each trial. (Subtract the volume of the water from the total volume of the water and solid.)

Trial 1:

50.7 - 50.2 = .5

Trial 2:

50.7 - 50.2 = .5

Trial 3:

50.5 - 50.1 = .4

2. Calculate the density of the irregular-shaped solid for each trial. (Divide the mass of the solid by the volume of the solid calculated above.)

Trial 1:

41.256 / .5 = 82.512

Trial 2:

42.299 / .5 = 84.598

Trial 3:

40.462 / .4 = 101.155

3. Part III: Density of Regular-Shaped Solid

1. Calculate the volume of the regular shaped solid for each trial.

(Multiply the length × width × height for each trial to get the volume in the unit cm3.)

Trial 1:

5.3 x 3 x 2.5 = 39.75

Trial 2:

5 x 4 x 3 = 60

Trial 3:

4.5 x 3.5 x 2 = 31.5

2. Calculate the density of the regular-shaped solid for each trial. (Divide the mass of the solid by the volume calculated above.)

Trial 1:

27 / 39.75 = .679

Trial 2:

27 / 60 = .45

Trial 3: 25.5 / 31.5 = .81

Questions and Conclusions:

1. How would you determine the proper number of significant figures of a liquid using a graduated cylinder? (See practice interactive in "Activity" tab of lesson.) The smallest