Practical 3 Sodium Thiosulfate

Question 1

Stage 1 method

Answer 1

1. Measure known volumes of reactants. Keep them separate so the reaction doesn’t start.
2. Place known volume of sodium thiosulphate into beaker with cross drawn underneath
3. Add second reactant. Start the stop watch when the last of the reactants is added to a conical flask.
4. Record time taken for cross to disappear
5. Repeat the experiment using the same total volume altering the volume of KI (see table).
6. Rate = 1/time
   Plot a graph of 1/t against vol of KI