Required Practical Rates Of Reaction

Question 1

What is the method of practical( disappearing cross)

Answer 1

• measure using measuring cylinder and put 10cm3 of sodium thiosulfate into conical flask
• place flask onto black Cross
• add 10 cm3 of hydrochloric acid into flask
• swirl solution into flask and time it until you can’t see the clock no more
• repeat experiment but with lower amounts of sodium thiosulfate
• calculate mean values of each experiment

Question 2

What’s the negatives of the disappearing cross experiment

Answer 2

-people have different eyesight