The Ideal Gas Equation

1
Chapter 19

• The Ideal Gas Equation

2
The Ideal Gas Equation
PV nRT

• P pressure
• V volume
• n number of moles
• T temperature
• R gas constant

3
R values
a
A
I
4
How many moles of gas will a 1250 cm3 flask hold
at 35.0?C and a pressure of 95.4 kPa?

• 0.0466 mol

5
What pressure in kPa is exerted by 0.00306mol of
gas in a 25.9cm3 container at 9.0C?

• 277 kPa

6
The Concorde, a supersonic passenger jet flew its
last flight on November 26, 2003. It was a major
pollution concern in that it produced 6.6 x 104
kg of CO2 for each hour of flight at 42 kPa and
627C. How many liters of CO2 is this?
7
The Concorde, a supersonic passenger jet flew its
last flight on November 26, 2003. It was a major
pollution concern in that it produced 6.6 x 104
kg of CO2 for each hour of flight at 42 kPa and
627C. How many liters of CO2 is this?

• 2.67 x 108 L 267,000,000 L

8
Gram Formula Mass (Molar Mass)

• The ratio of grams per mole.
• H2 2 g/mol
• CO2 44 g/mol
• H2O 18 g/mol
• We can therefore calculate gram formula mass if
  we know the grams and the moles.
• GFM grams/moles

9
A poisonous gas is leaking out of an old gold
mine. A chemist collects 4.564 grams of the gas
and uses the ideal gas equation to determine that
this is 0.163 moles. Is the gas CH4, CO, or AsH3
MM 28 g/mol
10
Remember our first question today.
11
How many moles of gas will a 1250 cm3 flask hold
at 35.0?C and a pressure of 95.4 kPa?

• n PV / RT 0.0466 mol
• 0.186 g of a gas at 35.0?C and 95.4 kPa occupies
  a volume of 1250 cm3. Is the gas H2, He, O2, or
  CO2?
• GFM grams/mole
• 0.186 g/0.0466 moles
• 3.99 g/mol 4 g/mol
• Therefore the gas is most likely He.

12
1.00g of a gas occupies 0.820 dm3 at 760 torr and
3.0C. The gas is most likely

• (a) BH3 (b) B4H10 (c) B2H6 (d) B3H12
  (e) B5H14

13
Homework

• Worksheet The Ideal Gas Equation