Quantitive Chemistry

• What is the volume occupied by one mole of any gas at 20 °C?

  24 dm³
• What does it mean that equal numbers of moles of any gas occupy the same volume at the same temperature and pressure?

  It indicates gas behavior under identical conditions
• How do you calculate the volume of a known mass of gas at r.t.p.?

  Volume = Mass × 24 / M
• What is the volume of 219.5 g of chlorine at r.t.p. if its molar mass is 71 g/mol?

  108 dm³
• How can you find the volume of one gas from the volume of another in a reaction?

  Use the mole ratio from the balanced equation
• How much carbon dioxide is formed when 30 dm³ of oxygen reacts with carbon monoxide?

  60 dm³ of CO₂
• What is concentration in chemistry?

  • Measure of how crowded substances are
  • Amount of solute in a given volume of solution
• What happens to the concentration of a solution as more solute is added?

  The concentration increases
• How do you calculate the concentration of a solution in g/dm³?

  Concentration = mass of solute / volume of solvent
• What is the concentration in g/dm³ of a solution with 30 g of sodium chloride in 0.2 dm³ of water?

  150 g/dm³
• How do you convert 500 cm³ to dm³?

  Divide by 1000 to get 0.5 dm³
• What is the concentration in mol/dm³ of a solution with 2 moles of salt in 500 cm³?

  4 mol/dm³
• What is the significance of the statement "any gas occupies the same volume under the same conditions"?

  It simplifies calculations for gas reactions
• What is the volume of 3.5 g of nitrogen (N₂) gas at room temperature and pressure?

  Calculate using the molar mass of nitrogen