Limiting Reactant

• What happens when hydrochloric acid reacts with calcium carbonate?

  It produces calcium chloride, water, and carbon dioxide
• How can we observe that a reaction is taking place between hydrochloric acid and calcium carbonate?

  Solid calcium carbonate disappears and gas bubbles form
• What indicates that one of the reactants has been completely used up in the reaction?

  The reaction stops and fizzing slows down
• What do we call the reactant that limits the amount of product produced?

  Limiting reactant
• What is the status of hydrochloric acid when calcium carbonate is the limiting reactant?

  Hydrochloric acid is in excess
• What happens if more calcium carbonate is added to the reaction?

  More fizzing occurs until calcium carbonate is used up
• What will happen if more hydrochloric acid is added without calcium carbonate?

  Nothing will happen as no reaction can occur
• What is combustion in the context of sodium burning in air?

  Reacting with oxygen
• What is the first step in calculating the mass of sodium oxide produced?

  Write and balance the chemical equation
• How do you calculate the number of moles of sodium?

  Using moles = mass / mr
• What is the number of moles of sodium in 115 grams?

  5 moles of sodium
• What is the mole ratio between sodium and sodium oxide?

  2 moles of sodium produce 1 mole of sodium oxide
• How many moles of sodium oxide are produced from 5 moles of sodium?

  2.5 moles of sodium oxide
• What is the formula to calculate the mass of sodium oxide?

  Mass = moles × mr
• What is the molar mass of sodium oxide (Na₂O)?

  62 g/mol
• What is the mass of 2.5 moles of sodium oxide?

  155 grams of sodium oxide
• What are the key concepts of limiting reactants?

  • Limiting reactant determines product amount
  • Excess reactant remains after reaction
  • Reaction stops when limiting reactant is used up
• What steps are involved in calculating the mass of a product from a limiting reactant?

  1. Write and balance the chemical equation
  2. Calculate moles of limiting reactant
  3. Determine mole ratio from balanced equation
  4. Calculate moles of product formed
  5. Find mass of product using mass = moles × mr