Test first

• What is the formula for calculating the mass of solute needed for a solution?

  Mass (g) = Volume (ml) × Concentration (g/ml)
• How many grams of sodium chloride are needed to make 36 ml of a 3% (w/v) solution?

  1. 08g
• What does (w/v) stand for in a solution concentration?

  Weight/Volume
• What is the concentration of sodium chloride in a solution if it is described as 4% (w/v)?

  It means there are 4 grams of sodium chloride in 100 ml of solution
• How much sodium chloride is contained in 90 ml of a 4% (w/v) solution?

  1. 6g
• What is the volume of sodium chloride solution in the flask?

  90 ml
• What is the concentration of sodium chloride in the solution?

  4% (w/v)
• How much sodium chloride is contained in 90 ml of a 4% (w/v) solution?

  1. 6 g
• How many flasks of 90 ml solution are needed to contain 7.2 g of sodium chloride?

  2 flasks
• What is the total volume of solution contained in 2 flasks of 90 ml?

  180 ml
• How many litres is 180 ml of solution?

  0.18 litres
• In which group of the periodic table is sulphur found?

  Group 6
• How many covalent bonds does sulphur normally form?

  2
• What is the typical number of valence electrons in sulphur?

  6
• Why does sulphur typically form 2 covalent bonds despite having 6 valence electrons?

  Because it can share 2 of its valence electrons to achieve a stable octet