Metric Measures
Length, Mass (Weight) & Density
PART I
MASS
Mass of an object, the amount of material it is, is closely related to its weight (a relation
of mass and gravity). Weighing an object with a scale or balance is finding its mass "here
on earth". Weights today will be measured using a triple beam balance unless otherwise
requested. Weights should be recorded to the nearest 0.01g (gram) on this scale.
A. Lead Object
a. Obtain a lead object from the instructor. Keep this item; you will be
making further measurements on it in Part II.
b. Obtain a weighboat. Measure and record its mass.
c. Place your lead object in the weighboat. Measure and record this new
(combined) mass.
d. Find, by subtraction, the mass of the lead object, record it.
B. Analytical Balance use (card & thumbprint, monofilament):
a. Obtain a "card" or piece of paper provided. Do NOT touch it; use tweezers
to move it.
b. Using the analytical balance, measure and record the card’s mass to the
nearest 0.0001g.
c. Move the card off the scale.
d. Place your thumb print on the card and apply fingerprint powder. Remove
excess powder.
e. Print your full name on the card (use a pencil or ballpoint pen).
f. Reweigh your card. Record this new (combined) mass.
g. Staple your thumbprint card to the back of your lab data sheet.
h. Find, by subtraction, the mass of your (processed) fingerprint and
signature, record it.
i. Find and record the mass of the three different strands of monofilament
provided. Return each to its proper envelope when finished.
C. Electronic Balance use:
a. Use a weighboat for all measurements. Tare (zero) out the weighboat
before placing objects into it for mass measurements.
b. Measure and record the mass of Object A in grams and in ounces (toggle
the readout mode!).
c. Measure and record the mass of Object B in grams and in ounces (toggle
the readout mode!).
d. Measure and record the mass of Object C in grams and in ounces (toggle
the readout mode!).
PART II
DENSITY
Density of an object is defined as its mass per unit volume. D=M/V
The mass is measured in grams (g) and the volume is measured in cubic centimeters (cm3
or cc) giving the units of g/cm3.
Density of Liquids
A. Water:
a. Weigh a clean, dry 10mL graduated cylinder. Record this weight.
b. Add tap water to your cylinder until you have (approximately) 8mL. Read
and record the exact volume of water in the cylinder to the nearest 0.1mL.
[Read the bottom of the meniscus or downwardly curved surface. Have the
surface at eye level or eye at surface level!]
c. Find and record the mass of the cylinder and water.
d. Find, by subtraction, the mass of the water, record it.
e. Compute and record the density of the sample of water.
B. Diesel Fuel or Mineral Spirits or Kerosene (as assigned):
a. Repeat the above procedures using about 8mL of the assigned fluid.
Density of Solids
A. Wood Block
a. Obtain a wood block and metric rule. Record the Block’s number.
Measure and record its length (L), width (W), and height (H) to the nearest
0.1cm.
b. Compute and record the volume of the Block. (vol = L x W x H)
c. Measure and record the mass of the Block.
d. Calculate and record the density of the block.
B. Lead Object
a. To a clean dry 10mL graduated cylinder add about 2-3mL of water. Read
and record the volume of water to the nearest 0.1mL.
b. Carefully place your lead object into the cylinder of water being careful in
not splashing any water out or up onto the cylinder sides.
c. Read and record this new volume.
d. Find, by subtraction, the volume of the lead object [amount of water
displaced]. [This is the water displacement technique for finding the
volume of an irregularly shaped object.]
e. Calculate and record the object’s density. Remember that you have
already measured the object’s mass in Part I.
f. Obtain and record the density of lead from the Handbook of Chemistry
and Physics.
g. Compare the two values for the density of lead (e. and f.). Calculate and
record the raw difference and the % difference between these two values.
% difference = (100 x [theoretical value – experimental value]) / theoretical value
Name________________________
Section________________
Metric Measures
Length, Mass (Weight) & Density
PART I
OBJECT MASSING
A. Lead Object
Mass of weightboat + lead object
_________________
Mass of weighboat
_________________
Mass of lead object
_________________
B. Card & thumbprint & signature [analytical scale]
Mass of card + thumbprint + signature
_________________
Mass of card
_________________
Mass of thumbprint + signature
_________________
Mass of monofilament A
_________________
Mass of monofilament B
_________________
Mass of monofilament C
_________________
C. Electronic top loading scale
Grams
Ounces
Mass of Object A
_________________
_________________
Mass of Object B
_________________
_________________
Mass of Object C
_________________
_________________
Name________________________
PART II
Section________________
DENSITY
A. Liquids
Water
Liquid #2 (________________)
Mass of graduated cylinder + liquid
_________________
_________________
Mass of graduated cylinder
_________________
_________________
Mass of liquid
_________________
_________________
Volume of liquid
_________________
_________________
Density of liquid
_________________
_________________
length: ________________
width: ________________
height: ________________
mass: ________________
volume: ________________
density: ________________
B. Wood Block # ____________
C. Lead Object
Volume before immersion
_________________
Volume after immersion
_________________
Mass of lead object
_________________
Volume of lead object
_________________
Density of lead object
_________________
Density of lead (handbook value)
_________________
Difference of densities
_________________
% difference of densities
________________