LAB #5 – Measurement: Mass, Volume, and the Exploration of Density

LAB #5 – Measurement: Mass, Volume, and the Exploration of Density

Introduction

Volume is the amount of space occupied by matter - solid, liquid, or gas.

Volume is measured in units: cm³ for a solid, mL for a liquid. 

Problem

-         A: How can we find the volume of a rectangular block? 

-         B: How can we find the volume of an irregularly

           shaped object?

Hypothesis:

-

Materials

-         Various sized blocks, irregular shaped objects, ruler, graduated cylinder

Procedure A

 1) Use a metric ruler to measure the dimensions of your rectangular objects; measure to the nearest tenth (0.1) cm.
 2) Calculate the volume in cm³ of your rectangular object by multiplying the length (cm) times the width (cm) times the height (cm). V = L x W x H
 3) Record your measurements in the data table.

Results A

Data Table: Volume of rectangular objects
        

Object	length (cm)	width (cm)	height (cm)	Volume (cm3)
A
B
C
D
E

   

V = L x W x H

cm³ = (cm)(cm)(cm)

Procedure B

Use a graduated cylinder to measure the volume of an irregular shaped solid. 
1. Fill the graduated cylinder to 50 mL and record this into your notebook.  This is your initial volume.
2. Carefully drop the object in on an angle.  The object will displace water (push water up to make way for the object) which will rise to make a new volume.
3. Subtract your initial volume from the new water level.

 Results B
Final Volume --------------à                _____mL
- Initial Volume ------------à                 _____mL
=Volume of irregularly shaped object: _____mL

Analysis B

1)  What is the maximum volume you can measure with this graduated cylinder?

2)  What is the smallest volume you can measure with this graduated cylinder?

3)   Determine the value of the minor grids on the cylinder.  i.e. how many mL does each line equal?

4)   Now, check to see if you’ve measured correctly using the Volume of a sphere equation:                                                    

Volume of sphere using equation:_____cm³

 Procedure C
The mass of an object is a measure of the number of atoms in it. The basic unit of measurement for mass is the gram (g).
You are going to calculate the densities of the wood blocks using the equation, Density = Mass/Volume.  You already have the volume of wood blocks A, B, C, D, and E in the data table for Results A.  You will use a triple beam balance to find the mass of each block, and then use the equation to find their volumes.  As always, make sure to include the proper units and round to the nearest tenth. 

Results C

Density = Mass/Volume 

Object	Mass (g)	Volume (cm3)	Density  ( g/cm3 )
A
B
C
D
E

Units:

Mass =        grams  =       g

Volume = cubic cm =     cm³ 

Density = ___     hint: D=M/V

Analysis C

1)  Calculate: Combine the densities of blocks A, B, C, D and E to find the average density for the wood.  Show your work.

2)  What is the maximum mass the triple beam balance can measure?

3)  What is the minimum mass the triple beam balance can measure?

4)  What are the units for the triple beam balance?

5)  Why is it called a triple beam balance?  What does each beam measure; think in numerical terms.

6)  Why is it necessary to zero your triple beam balance before using it?


Analysis B

1) What is the maximum volume you can measure with this graduated cylinder?

2) What is the smallest volume you can measure with this graduated cylinder?

3)  Determine the value of the minor grids on the cylinder.  i.e. How many mL does each line equal?

4) Now, check to see if you’ve measured correctly using the Volume of a sphere equation:                                     

5) How can you use a graduated cylinder to measure the volume of a liquid?

6) What happens to the volume of the liquid when you drop an object into the graduated cylinder?  How can we use this to help us find the volume of the object?

7) If an object dropped into the graduated cylinder pushes up the water mark from an initial volume of 25 ml to a final volume of 51.5 ml, how many cm³ is the object?

8) Compare the two different methods of obtaining volume of a marble, how did you do?  How far off were your calculations?

9) Go back to Lab #2 – Crazy Coasters

Mass of glass marble:    _____

Volume of glass marble: _____

Density of glass marble: _____

Predict: Would you expect the glass marble to sink or float based on its density?  Why? 

10) Marble (glass), Wood blocks (wood), Water (liquid H₂O): List them in order from least dense to most dense; use data from this lab to support this. 

  **Round each answer to the nearest tenth**

++Include units++

Conclusion

What was your problem?

Restate your hypothesis.  Was it right? wrong?  why or why not?

What did you learn in this lab?

What did you like about this lab?

What were some challenges you had to deal with?

What could you do next with this problem?  What other tests could you perform?

Write down any other additional thoughts, observations, inferences, etc.