Gases and Solutions

• What volume does one mole of any gas occupy at 20 °C?

  24 dm³
• How do you calculate the volume of gas?

  Volume = Mass / Molar mass x 24
• How can you find the volume of one gas in a reaction?

  Use the volume of another gas
• What is concentration in chemistry?

  • Measure of how crowded substances are
  • Amount of substance in a certain volume
  • Expressed in mass/volume or moles/volume
• How do you calculate the mass of a solute in solution?

  Mass = concentration x volume
• What is the formula for concentration in mol/dm³?

  Concentration = moles of solute / volume of solvent
• What is the formula for concentration in g/dm³?

  Concentration = mass of solute / volume of solvent
• What is the concentration of sodium chloride in g/dm³ if 30 g is dissolved in 0.2 dm³?

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

  Divide by 1000
• What is the concentration in mol/dm³ of 2 moles of salt in 500 cm³?

  4 mol/dm³
• Why is it significant that any gas occupies the same volume under the same conditions?

  It simplifies calculations in gas reactions
• How would you calculate the volume of 3.5 g of nitrogen gas at room temperature and pressure?

  Use the formula: Volume = Mass / Molar mass x 24