Density of Solids Lab

  1. Read the lab guide carefully, plan and prepare your notecard, and review the lab write-up procedures. We will do the write-up together in class. Each member of the lab group should understand the steps before performing the lab.

  2. Using normal observation, try to identify each of your samples. For solids with a regular geometric shape use Run 1 procedure, for irregular solids, use Run 2 procedure. For the metal cylinder use both procedures and we can compare your results.

  3. You must make all measurements needed first. After all data collection is made you may begin your calculations.

  Run 1 - Procedure for regular geometric solids

Thoroughly dry the solid objects. Mass each accurately. Record the measurements needed on your notecard. You will be using rulers and vernier calipers to make the measurements.

  Run 2 - Procedure for irregular solids

Dry the objects and mass each separately. Use the graduated cylinder to find the volume of these objects by water displacement. Remember to read the graduated cylinder to the tenths place. Remember to place it on the counter and read the bottom of the meniscus.

Formulas that may be needed:

density = mass/volume

volume of sphere = 4/3 p r³                      p = 3.1416

volume of cylinder =  p r² L

radius of sphere = circumference/2p  or diameter/2

volume of rectangle = length x width x height  

% difference = | difference of two densities / larger of two densities | x 100 = ____%

        

 

Questions to be answered in lab write-up:

1. How would you find the density of an irregular shaped object that would not fit in any graduated cylinder?

2. How would air bubbles sticking to an object affect your volume measurement?

3. Devise a method for obtaining the volume of a teaspoonful of sugar crystals, remembering that sugar will dissolve in water.

4. A submarine rises and sinks by changing its density. If the density changes, its mass or volume or both must change. Explain how a submarine rises and sinks using density.

5. The density of ice is 0.92 g/cm³. The mass of a block of ice is 2.0 kg. What is its volume? Show your work here. How does the ice have a density lower than that of water itself?

6. How do you measure the volume of an object that floats?

7. Try to explain density on an atomic or molecular level.