Concentrations

• How do you calculate the concentration of a solution in g dm⁻³?


  By measuring the mass of solute in grams and dividing by the volume of solution in dm³.
• How do you calculate the concentration of a solution in mol dm⁻³?


  By dividing the number of moles of solute by the volume of solution in dm³.
• How do you convert a concentration in g dm⁻³ into mol dm⁻³?


  By dividing the concentration in g dm⁻³ by the relative formula mass of the solute.
• What is the purpose of a volumetric flask in solution preparation?


  • To accurately measure a specific volume of solution
  • Common volumes include 100.0 cm³, 250.0 cm³, or 1000 cm³
  • Ensures precise concentration of the solution
• What is the correct method to measure the volume of liquid in a volumetric flask?


  Measure from the bottom of the meniscus at eye level with the graduation mark.
• What are the units of concentration typically used for solutions?


  g dm⁻³ and mol dm⁻³.
• What does 1 dm⁻³ represent in terms of volume?


  1 litre or 1000 cm³.
• How is the concentration of a solution often expressed?


  As the number of moles of solute dissolved in 1 dm³ of solution.
• How do you calculate the concentration in mol dm⁻³ using the formula?


  $\text{concentration in mol dm}^{-3} =$$\frac{\text{number of moles of solute}}{\text{volume of solution in dm}^3}$
• What is the concentration of 1.0 mol of potassium chloride in 4.0 dm³ of solution?


  $0.25 \text{ mol dm}^{-3}$
• What is the concentration of 0.15 mol of copper sulfate in 250 cm³ of solution?


  $0.6 \text{ mol dm}^{-3}$
• How do you calculate the number of moles of sodium sulfate in 100 cm³ of a solution with a concentration of 0.25 mol dm⁻³?


  $0.025 \text{ moles}$
• How do you calculate the volume of solution in cm³ containing 0.02 mol of potassium hydroxide at a concentration of 0.5 mol dm⁻³?


  $40 \text{ cm}^3$
• How are the two types of concentrations related?

  $\text{concentration in mol dm}^{-3} =$$\frac{\text{concentration in g dm}^{-3}}{\text{relative formula mass of solute}}$
• What is the concentration in mol dm⁻³ of sulfuric acid, H₂SO₄, with a concentration of 196 g dm⁻³?


  $1.0 \text{ mol dm}^{-3}$
• What is the concentration in mol dm⁻³ of hydrochloric acid, HCl, with a concentration of 1.825 g dm⁻³?


  $0.5 \text{ mol dm}^{-3}$
• What is the concentration in g dm⁻³ of sodium hydroxide, NaOH, with a concentration of 6.0 mol dm⁻³?


  $240 \text{ g dm}^{-3}$
• What is the concentration in g dm⁻³ of sodium chloride, NaCl, with a concentration of 0.125 mol dm⁻³?


  $7.35 \text{ g dm}^{-3}$
• What is Mole Day and when is it celebrated?


  • Celebrated between 6.02 am and 6.02 pm on 23 October
  • Honors Avogadro's number, \(6.02 \times 10^{23}\)
• What is Avogadro's number?


  It is \(6.02 \times 10^{23}\).
• How can you assess your confidence in answering the progression questions?


  By reflecting on your understanding and ability to solve the related problems.
• How do you calculate the concentration of sodium hydroxide, NaOH, with a concentration of 32 g dm⁻³ in mol dm⁻³?


  $0.8 \text{ mol dm}^{-3}$
• How do you calculate the concentration of sodium carbonate, Na₂CO₃, with a concentration of 106 g dm⁻³ in mol dm⁻³?


  $1.0 \text{ mol dm}^{-3}$
• How do you calculate the mass of potassium chromate, K₂CrO₄, needed to make 250 cm³ of a 0.02 mol dm⁻³ solution?


  $0.25 \text{ g}$
• How do you calculate the number of moles in 250 cm³ of a 0.15 mol dm⁻³ potassium dichromate solution?


  $0.0375 \text{ moles}$
• How do you calculate the mass present of potassium dichromate in 250 cm³ of a 0.15 mol dm⁻³ solution?


  $3.75 \text{ g}$