Gas Stoichiometry

1
Gas Stoichiometry

• Non-Standard Conditions

2
Nonstandard Conditions

• Gas volume changes dramatically when pressure or
  temperature change.
• Key The mole-mol calculation must take place at
  STP.

3
Doing the Calculations

• Given a volume of gas at other than STP?
• Convert to STP before doing the mole-mole
  calculation.
• Finding the volume of gas at other than STP?
• Do the mole-mole step, then convert the volume to
  stated conditions

4
Problem 1

• What volume of chlorine gas measured at 18.5oC
  and 98.0 kPa can be produced by the electrolysis
  if 62.3 g of NaCl to give sodium metal and
  chlorine gas?
• Answer 13.2 L

5
Problem

• 2.00 g of sucrose is combusted in excess oxygen.
  What is the volume of dry CO2 that is formed at 1
  atm pressure and 37oC?
• MW sucrose 342.3 g/mol
• C12H22O11 12O2 ? 12CO2 11H2O
• A. 22.4 L
• B. 10.4 L
• C. 1.78 L
• D. 0.545 L
• E. 0.148 L

6
Problem

• 2.00 g of sucrose is combusted in excess oxygen.
  What is the volume of dry CO2 that is formed at 1
  atm pressure and 37oC?
• MW sucrose 342.3 g/mol
• C12H22O11 12O2 ? 12CO2 11H2O
• A. 22.4 L
• B. 10.4 L
• C. 1.78 L
• D. 0.545 L
• E. 0.148 L