quantitative chemistry

• What is Relative Atomic Mass (Ar) compared to?

  Carbon-12
• Where can Relative Atomic Mass (Ar) be found?

  On the periodic table
• What is the Relative Atomic Mass (Ar) of Carbon?

  12
• What is the Relative Atomic Mass (Ar) of Oxygen?

  16
• What does Relative Formula Mass (Mr) represent?

  Sum of Ar values in a compound
• How do you calculate the Relative Formula Mass (Mr) of H₂O?

  (2×1)+(1×16)=18
• What is a mole in chemistry?

  Quantity containing 6.02 × 10²³ particles
• What is Avogadro’s constant?

  6.02 × 10²³ particles per mole
• How many grams are in 1 mole of an element?

  Equal to its Relative Atomic Mass (Ar)
• How many grams are in 1 mole of a compound?

  Equal to its Relative Formula Mass (Mr)
• What is the formula to calculate moles?

  Moles = Mass (g) / Mr
• How many moles are in 36g of H₂O?

  2 moles
• What is the formula for concentration of solutions?

  Concentration = Moles / Volume (dm³)
• What is the volume conversion between dm³ and cm³?

  1 dm³ = 1000 cm³
• What is the concentration of 0.5 moles of NaCl in 250 cm³ solution?

  2 mol/dm³
• What do balanced equations show in stoichiometry?

  Mole ratios of reactants and products
• How many moles of H₂ react with O₂ in the equation 2H₂ + O₂ → 2H₂O?

  2 moles of H₂
• What are the steps to calculate reacting masses?

  Balance equation, find moles, use ratio, convert to mass
• What mass of H₂O is produced from 4g of H₂ reacting with oxygen?

  36g
• What is the formula for percentage yield?

  % Yield = (Actual Mass / Theoretical Mass) × 100
• What are some reasons for low yield in reactions?

  Reversible reactions, side reactions, loss during filtration
• What does atom economy measure?

  Efficiency of a reaction
• What is the formula for atom economy?

  % Atom Economy = (Mr of Desired Product / Total Mr of Reactants) × 100
• What does higher atom economy indicate?

  Less waste produced in a reaction
• What volume does 1 mole of any gas occupy at RTP?

  24 dm³
• What is the formula for gas volume calculations?

  Volume = Moles × 24
• What volume does 2 moles of CO₂ occupy?

  48 dm³