disappearing cross
The Disappearing Cross Aim: I¡¯m going to investigate the effects of how the concentration of sodium thiosulphate effects the reaction with hydrochloric acid. Introduction: You¡¯re able to easily measure the rate of reaction because solid sulphur is formed and obscures the cross. ... Method: In my experiment I¡¯m going to record how long it takes the cross to ¡®disappear¡¯ underneath a flask that contains each time 5cm©ø of hydrochloric acid and various dilutions of sodium thiosulphate. ... The Disappearing Cross. ... 5g 4 The Disappearing Cross Now for the actual investigation I should firstly pour 50ml of the undiluted solution of sodium thiosulphate in to a beaker that is placed on top of a piece of paper with the black cross on it. ... Once the liquid has gone completely cloudy, so much that you can¡¯t see the cross anymore, I¡¯ll stop the stop clock and record my results. ... Results Molarity of solution First experiment(Seconds) Second experiment(Seconds) Average(Seconds) Reaction time=/time for cross to disappear.