22.4 l moles, volume and density. calculate the volume of a given mass of a gaseous substance from...
TRANSCRIPT
22.4 L
Moles, volume
and density
• Calculate the volume of a given mass of a gaseous substance from its density at a given temperature and pressure.
Include: molar volume calculation • Solve problems requiring interconversions
between moles, mass, volume, and number of particles.
Additional KEY TermsSTP
Avogardo (1776-1856)
Avogadro’s Hypothesis - any sample of any gas at the same temperature and pressure will contain the same number of particles.
Chemists use a standard temperature and pressure, STP, to measure gas volumes.
0°C and 101.3 kPa
At STP:The volume of 1 mole of ANY GAS is 22.4 L.
22.4 L/mol is known as molar volume.
The MASS of 22.4 L of any gas is equal to themolar mass for that gas.
How many moles are in 50.0 L of Fluorine gas atSTP?
F2 = 36.0 g/mol
50.0 L22.4 L1 mol = 2.23 mol
What is the STP volume of 10.0 g of Methane gas?
CH4 = 16.0 g/mol
10.0 g16.0 g1 mol = 14.0 L
1 mol 22.4 L
Density: A physical property that describes the mass per unit volume of a substance.
grams (g) per litregrams per mL (or cm3)
Calculate the volume, in litres, of one mole ofammonia (NH3) at room temperature if the densityis 0.696 g/L.
NH3 = 17.0 g/mol
1 mol 1 mol
17. 0 g= 24.4 L 0.696 g
1 L
Calculate the volume, in litres, of two moles of carbon dioxide, at room temperature, when the density is 1.80 g/L.
CO2 = 44.0 g/mol
2 mol 1 mol
44. 0 g= 48.9 L 1.80 g
1 L
· STP: 0°C and 101.3 kPa (1 atm)
· At STP, the molar volume of any gas is 22.4 L
· Molar mass = total grams in 1 mole (g/mol)
· 1 mole = 6.02 x 1023 particles (Avogadro)
· density of a substance = mass per volume (g/L)
* All roads lead to moles (convert to moles first).
CAN YOU / HAVE YOU?
• Calculate the volume of a given mass of a gaseous substance from its density at a given temperature and pressure.
Include: molar volume calculation • Solve problems requiring interconversions
between moles, mass, volume, and number of particles.
Additional KEY TermsSTP