Density and Moles

Density:

- is a measure of mass per volume.
- is measured in g/mL or g/L
- Formula for density is
         

Example:

Oxygen has a density of 1.0 g/ml. Determine the mass of 11.5 mL of oxygen gas.

11.5 mL x 1.0 g      = 11.5 g
                  1 mL

How many moles are there in 11.5 mL of oxygen?

11.5 g x 1 mol   =  0.639 mol
                18 g


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Density of gases:

The density of gases can vary with the temperture.
If the temperature is at STP, we can find density by "

Molar Mass
22.4 L/mol

Example:

32g/mol       = 1.4 g/ L
22.4L/mol

-Candace Chan