Stoichiometry of Gases

1
Stoichiometry of Gases

• 11-3

2
Volume-Volume calculations

• FOR GASEOUS REACTANTS AND PRODUCTS ONLY!!!!!!!

Coeffficients of Balanced Equation


Mole Ratio
VOLUME RATIO !
3
Example problem

• Nitrogen reacts with hydrogen to form gaseous
  ammonia. What volume of hydrogen is needed to
  react with excess nitrogen in order to form 1.50
  L ammonia? Assume that all measurements are made
  at the same temp and pressure.

4
All other situations

• You must do the all of the steps of stoichiometry.

5
Volume Mass and Mass- Volume Calculations

• Same logic as mass-mass problems
• Get all of your given information (mass or
  volume) into moles
• Use the balanced equation to transition from
  moles of the given info into moels of what you
  need to find
• Change the mole value into the appropriate mass
  or volume units

6
Sample problem

• When arsenic (III) sulfide is roasted in air, it
  reacts with oxygen to produce arsenic(III) oxide
  and sulfur dioxide. What volume of sulfur
  dioxide, at 20C and 98.0 kPa, is produced from
  89.5 g of arsenic (III) sulfide?

7
Sample 2

• Dinitrogen monoxide can be prepared by heating
  ammonium nitrate. Water is the other product.
  What mass of ammonium nitrate should be
  decomposed in order to produce 250.0 mL of
  dinitrogen monoxide
• A) at STP
• B) at 21.0 C and 102.4 kPa