Stoichiometry Practice Problems

Stoichiometry Practice Problems

• Water Formation from Hydrogen and Oxygen

  • Reaction: 2H2 + O2 → 2H2O
  • To produce 5.0 moles of water, 5.0 moles of H2 are required.

• Mass of Water from Oxygen

  • Given 384 g of O2, the mass of water (H2O) formed is 432 grams.

Sulfuric Acid and Sodium Hydroxide Reactions

• H2SO4 and NaOH Reaction

  • Reaction: H2SO4 + 2NaOH → Na2SO4 + 2H2O
  • 36.8 grams of H2SO4 are needed to react with 0.75 mol of NaOH.

• Water Production from H2SO4

  • When 30.0 g of H2SO4 reacts with NaOH, it produces 11.0 grams of water.

Tin and Hydrofluoric Acid Reactions

• Sn and HF Reaction

  • Reaction: Sn + 2HF → SnF2 + H2
  • 30.0 g of HF produces 117 grams of SnF2.

• HF Requirement for Tin

  • 48 grams of Tin (Sn) requires 0.81 moles of HF for reaction.

Carbon Dioxide Removal in Spacecraft

• Reaction with Lithium Hydroxide
  • Reaction: CO2(g) + 2LiOH(s) → Li2CO3(s) + H2O(l)
  • 20.0 moles of exhaled CO2 produce 148 grams of Li2CO3.

Sodium Reaction with Water

• Sodium and Water Reaction
  • Reaction: 2Na + 2H2O → 2NaOH + H2
  • 5.0 grams of water yields 0.14 moles of H2.

Decomposition of Potassium Chlorate

• KClO3 Decomposition Reaction
  • Reaction: 2KClO3 → 2KCl + 3O2
  • 10 moles of KClO3 produces 15 moles of O2.

Lithium Hydroxide and Hydrobromic Acid Reaction

• LiOH and HBr Interaction
  • Reaction: LiOH + HBr → LiBr + H2O
  • 10 grams of lithium hydroxide produces 36.3 grams of lithium bromide.

Combustion of Ethylene

• Ethylene and Oxygen Reaction
  • Reaction: C2H4 + 3 O2 → 2 CO2 + 2 H2O
  • Starting with 45 grams of ethylene produces 141.4 grams of carbon dioxide.

Hydrochloric Acid and Sulfuric Acid Reaction

• HCl Reaction with Na2SO4
  • Reaction: 2HCl + Na2SO4 → 2 NaCl + H2SO4
  • 20 grams of hydrochloric acid produces 26.9 grams of sulfuric acid.

Lithium Hydroxide and Potassium Chloride Reaction

• LiOH and KCl Reaction
  • Reaction: LiOH + KCl → LiCl + KOH
  • 20 grams of LiOH yields 35.5 grams of LiCl.

Combustion of Propane

• Propane and Oxygen Reaction
  • Reaction: C3H8 + 5 O2 → 3 CO2 + 4 H2O
  • 5 grams of propane results in 8.2 grams of water.

Boron Hydride and Oxygen Reaction

• B2H6 Combustion

  • Reaction: B2H6 + O2 → HBO2 + H2O
  • 36.1 g of B2H6 requires 125 grams of O2 for complete combustion.

• Moles of Water Produced from B2H6

  • 19.2 g of B2H6 produces 1.39 moles of water.

Reaction Quantities in Potassium Oxalate

• Potassium Oxalate Reaction

  • Reaction: 5 K2C2O4 + 2 KMnO4 + 8 H2O → 10 CO2 + 2 Mn(OH)2 + 12 KOH
  • For 25.0 g of K2C2O4, 9.51 grams of KMnO4 are needed.

• Mn(OH)2 Production

  • From the same amount of K2C2O4, 5.35 grams of Mn(OH)2 are produced.

Molar Relationships in Reactions with Hydrogen

• Hydrogen Reaction Requirements
  • 2H2 + O2 → 2H2O: To react completely with 2.00 moles of H2, 1 mole of O2 is needed.
  • The complete reaction of 2.00 moles of H2 results in 2 moles of H2O.

Ammonia Reactions

• Ammonia with Oxygen Reaction
  • Reaction: 2NH3 + 2O2 → N2O + 3H2O
  • 3.00 moles of NH3 require 3 moles of O2 and yield 4.5 moles of H2O.
  • This reaction also produces 1.5 moles of N2O.