rates of reaction

• 1 - These two chemicals are clear solutions and react together to form a yellow precipitate of sulfur. use a measuring cylinder to measure 10cm cubed of sodium thiosulfate solution into a conical flask. place conical flask on printed black cross
• 2 - add 10cm cubed of hydrochloric acid to the conical flask. stir the solution and start a stop watch. after a certain of time the solution turns cloudy, once you can no longer see the cross, stop the stop watch
• 3 - repeat experiment using lower concentrations of sodium thiosulfate solution. Do this another 2 times and calculate a mean value
• SODIUM THIOSULFATE AND HCL PRODUCE A CLOUDY PRECIPITATE
• the higher the concentration, the quicker the reaction and therefore the less time it takes for the mark to disappear