rates of reaction

Question 1

PRACTICAL - explore effect of concentration on rate of reaction using a cross

Answer 1

• Add 10cm³ of sodium thiosulfate solution in a conical flask
• place the conical flask onto a drawn black cross
• then add 10cm³ hydrochloric acid into the conical flask
• swirl the solution and start a stopwatch
• solution will start to become cloudy
• stop the stopwatch when you can no longer see the cross
• repeat using lower concentrations of sodium thiosulfate solutions

Question 2

PRACTICAL -measuring volume of a gas produced by a reaction

Answer 2

• add 50cm³ of hydrochloric acid into a conical flask
• attach conical flask to bung and delivery tube
• place delivery into container filled with water
• place an upturned measuring cylinder also filled with water over the delivery tube
• add one magnesium ribbon to the hydrochloric acid and start a stopwatch
• hydrogen gas will be produced and be trapped in the measuring cylinder
• measure volume of hydrogen gas in cylinder every 10s
• continue until no more hydrogen is given off
• repeat using different concentrations of hydrochloric acid