C3- quantitative chemistry

• What principle must be followed when balancing chemical equations?

  Conservation of mass
• The relative formula mass of CO2 is 44
• If a gas product escapes during a reaction, the mass of the reactants appears to decrease
• What is a mole defined as?

  A specific number of atoms
• One mole of carbon has a mass of 12
• What is the equation to calculate the number of moles?

  Moles = mass / Ram
• The term Ram can refer to both relative atomic mass and relative formula mass
• What is the stoichiometry of the methane combustion reaction for oxygen and methane?

  2:1
• If 64g of methane reacts completely, the mass of water produced is 144g.
• Steps to calculate the mass of a product from the mass of a reactant

  1️⃣ Calculate the moles of the reactant

  2️⃣ Use stoichiometry to find moles of product

  3️⃣ Calculate the mass of the product
• What is the limiting reactant in a reaction?

  The reactant that runs out first
• The concentration of solutions can be expressed in grams per cubic decimeter.
• What is the concentration of a solution if 1 mole of HCl is dissolved in 1 dm³ of water?

  1 mole per dm³
• Reversible reactions reach a state of equilibrium
• What does percentage yield measure?

  Actual product vs theoretical
• You can predict percentage yield directly from a balanced chemical equation.

  False
• Atom economy measures the efficiency of mass in a reaction.
• What is the formula for atom economy?

  (Desired product Ram / total reactants Ram) * 100
• Atom economy can exceed 100% in some reactions.

  False
• What is the relative formula mass of CO₂?

  44
• One mole of any gas occupies a volume of 24 dm³ at RTP.
• What are the conditions defined as RTP?

  20°C and 1 atm