Calculating the Rate of Reaction

• rate of reaction formula

  amount/time
• what does the amount refer to in the rate of reaction formula?

  amount can either be:

  • amount of reactant used
  • amount of product formed
• how can you measure the amount of reactants used if one of the products is a gas in rate of reaction?

  • measure the mass in grams (g) of the reaction mixture BEFORE and AFTER the reaction takes place
  • measure the time it takes for the reaction to happen

  The mass of the mixture will decrease

  The units for rate of reaction may then be given as g/s
• what can the amount of a reactant also be measured in other than g/s?

  moles (mol)

  • as the reaction takes place, the reactant is used up so the amount of reactant remaining decreases
  • concentration of the reactant is calculated -> amount/vol
  • units= mol/dm³
• how can you measure the amount of products formed in rate of reaction if one of the products is a gas?

  • measure the total volume of gas produced in cm³ with a gas syringe
  • measure time it takes for reaction to happen
  • units can be given as cm³/s
• how can you measure the rate of reaction by measuring the time it takes for a reaction mixture to become cloudy or change colour?

  • measure how long it takes for the mixture to change colour]
  • rate of reaction = 1/time taken for solution to change colour