1. Warm-Up: Percent Error
1) True value = 21.2g, Measured value = 17.7g
2) True value = 4.15ml, Measured value = 4.26 ml.
17% 2) 2.7%

2. Density

3. Mass: the amount of matter in an
object
Volume: the amount of space
something takes up

4. m D= v The formula for density is:
Density calculates the mass per unit of volume
Physical property of matter/substances
Provides information on how solids/liquids interact
Ratio of a substance’s mass and volume
The formula for density is: m D= v

5. To calculate density you need to do two things:
To find the mass
use a balance
2) To find the volume

6. How can we calculate the volume????
use a ruler (l x w x h)
use a graduated cylinder for liquids
water displacement method for irregular objects

7. The units for density are:
g/cm3 (if we use the ruler
for solids)
g/mL (if we use the cylinder
for liquids)

8. *Note:
The density of a substance is unique to that substance – it’s like a fingerprint!

9. * Gasoline .67 g/mL Ice .92 g/cm3 Water 1.00 g/mL Sugar 1.587 g/mL
Mercury g/mL
Gold g/cm3 *

10. What if. . .
We mix several different liquids together (water, gas, and mercury) in a two liter bottle, shake the bottle, and allow the liquids to settle. What would it look like?
Densities
Water g/mL
Gasoline g/mL
Mercury (a liquid metal) g/mL

11. Gasoline .67 g/mL Water (liquid) 1.00 g/mL ** Mercury 13.54 g/mL
This is called a density column!
Gasoline
Water
Mercury

12. Solving Density Problems
1st: write down the equation
2nd: write down what you are
given (include the units)
3rd: make sure you don’t
have to convert units
4th: SOLVE!

13. Example 1: A student obtains a mass of 5
Example 1: A student obtains a mass of 5.03 g for a metal and a volume of 3.24 ml?
1.55 g/ml

14. Example 2: What is the volume of a substance with a density of 0
Example 2: What is the volume of a substance with a density of g/ml and a mass of 0.451g?
0.547 ml

15. Example 3: A student records V1= 2. 7ml and V2= 3
Example 3: A student records V1= 2.7ml and V2= 3.4 ml after placing an object in a graduated cylinder. The mass of an empty beaker is 1.13g and the mass of both the beaker and substance is 4.13g. What is the object’s density?
4.3 g/ml