What would the chemical equation/equations for the reaction in the following experiment be? And what is happening to cause the pH increase?
• Dissolve 0.37 g of sodium thiosulfate in 200 mL of water in a beaker.
• Dissolve 9 g of potassium iodide in a separate 200 mL of water in a beaker.
• Combine these solutions in the volumetric flask.
• Add 4 mL of 0.1M ethanoic acid, then add water to adjust the total volume to 500 mL.
• Measure 100 mL of solution A into a 250 mL beaker and mix in 3 drops of universal indicator.
• Freshly prepare 0.056M of hydrogen peroxide by diluting 7 mL of 6% hydrogen peroxide solution with 250 mL of water.
1. In a beaker, mix 100 mL of solution A with 30 mL of solution B.
2. Start the stopwatch from the time that solution A and B are combined, to the time at which the colour transitions from red, orange, yellow, etc... to a dark purple.