Density and Moles

Today's class (November 4), We learned how to calculate the density of gases at STP (Standard Temperature and Presssure)

-density equals the mass per unit volume
-an easy way to rememeber how to calculate Mass, Density and Volume is to picture it as a triangle with Mass on top and Density and Volume on the bottom
-to calculate the density of gases at STP we follow this equation

DensitySTP=Mass of 1 mole\Volume of 1 mole=Molar Mass\22.4 L=g per mol\L per mol


Examples:

1. Calculate the density of O2 @ STP

Dstp=32 g per mol\22.4 L per mol=1.43 g per L

2. The density of a gaseous mixture of C8H18 @STP=?

D=M\V
D=114\22.4
D=5.1 g per L

3. Calculate the density of Dihydrogen Phosphate

D=M\V
D=97\22.4
D=4.3 g per L



D&V-mass=d x v-MASS-molar mass-MOLE-6.02x10 to the 23-MOLECULES-subscripts-ATOMS