Volume
p184
• What is volume:
It is the measurement of the amount of space
an object can occupy. It may be solild, liquid or
gas.
Units of Volume
• Millilitre (mL)
• Litre (L)
1 mL = 1 cm
• Cubic centimetres (cm3)
• Cubic millimitre (mm3)
• Cubic meter (m3)
3
Taking a reading on a graduated cylinder
• To know the value of each graduation:
- Find two major graduations.
- Substract them from eachother.
- Divide by the number of spaces. Example:
-Two major graduations
25 et 30
-So 30 – 25 = 5
-There are 5 spaces so:
5/5=1
- Each graduation is worth 1.
A) Volume of a liquid
• The instruments are:
- Graduated cylinders, beakers, erlenmeyer flask,
etc.
• The meniscus:
When the liquid is not perfectly flat, it will curve a
little. You have to read under the meniscus.
Meniscus
Meniscus
53 mL
To measure 10 mL, you must pour 10 mL of water in the graduated cylinder and
read under the menuscus.
18 mL
400 mL
You can try!
B) Regular solid
• Use a ruler to measure the sides.
• For a rectangular prism or cube, use the
following formula:
V= Length x Width x height
- Cylinder: V=πXr2Xh.
π = 3.14
r = radius
h = height
• Example 1: 2 cm X 3 cm X 5 cm = 30 cm3
• Example 2: 3,14 x 1,52 x 8 = 56,52 cm3
You can try!
= 8 cm
3 cm
5 cm
r = 1.5 cm
2 cm
C) Irregular solid
• Example: a nail, a penny, an eraser, a paperclip
etc.
• You will need a graduated cylinder or an
overflow can.
Water displacement method
• Fill the graduated cylinder with water and write down the
volume. (example 20 mL)
• Place the solid into the cylinder and read the new volume.
• Subtract the first reading from the second reading. The
difference is the object’s volume.
You can try!
Volume =
40 mL - 30 mL = 10 mL
Overflow can
-Place a beaker under the overflow can
- Fill up the overflow can until the water is
overflowing.
-Place the object in the can.
- Collect the water that overflows and measure its
volume.
Volume lab activity
Object
Small metal cylinder
Large metal cylinder
Rectangular prism
Marble
Rubber stopper
Volume measured
with a ruler
Volume measured by
water displacement