1. Density Ratio of mass of object to its volume Density = Mass / volume
= g / cm3

2. Example
What is the density of 35.0 g of a substance with a volume of 25.0 cm3?
D = m / v
=35.0g / 25.0 cm3
=1.40 g / cm3

3. Practice
What is the density of 2.75 kg of substance with volume of 250 cm3?
D = M / V D= 2.75 kg / 250 cm3
= 2750 g / 250 cm3
= 11 g /cm3

4. Determine the volume of 35.2 g of CCl4 if the density is 1.60 g /cm3.
D = M / V
1.60 g / cm3 = 35.2 g / V
(1.60 g / cm3) V = 35.2 g
V = 35.2 g / (1.60 g/ cm3)
V = 22.0 cm3

6. How does density change as volume decreases?
Density is an intensive property
(Does not depend on amount of matter present.)

8. Specific Gravity
Compares density of a substance with the density of a reference substance- usually water- usually both substances at same temperature

9. Specific gravity has NO units Measured with a hydrometer.
Specific Gravity = Density of substance (g/cm3)
Density of water (g/cm3)
Units cancel out
Specific gravity has NO units
Measured with a hydrometer.

11. Hydrometers Used to measure: Strength of anti freeze in radiation
Strength of acid in lead-acid battery