Chemistry Notes
Unit 2: Density
Density
Recall:
 Mass – amount of matter in an object (g)
 Volume – the amount of space an object
takes up (ml)
Density
Density = mass per unit volume
 Density is a derived unit
 Densities of materials can change with
temperature
 Examples of units for density


g/cm3, kg/m3, g/mL, kg/L
Equation for Density
D=m/V
Density

Both blocks have the same volume, which
has a higher density? Why?
Density
Measuring Density
 After finding mass on a balance or scale, the
volume can be calculated (4/3 π r2, l X w X h,
etc.  divide mass by volume  density
 After finding mass on a balance or scale, the
volume can be measure using a graduated
cylinder  divide mass by volume  density
 Calculate the density of Object A (m = 35g
and v = 124 mL)
D = 35 g / 124 mL = 0.2823 g/mL
Density
Solving for mass given the density
 Calculate the mass of Object B
(D = 2.164 g/cm3, v = 300 cm3)
 Start with equation; D = m / v
 Plug in known quantities;
2.164 g/cm3 = m / 300 cm3
 Solve: Answer 649.2 g
Density
Solving for volume given density
 Calculate the volume of Object C
(D = 1.87 g/cm3, m = 600g)
 Start with equation; D = m / v
 Plug in known quantities;
1.87 g/cm3, m = 600 g
 Solve: Answer 320.86 cm3
Density

Density is the
measure of particles
per unit volume.

Density can describe
states of matter
Density

Questions?