Rp 03- Effect Of Temperature On Rate Of Reaction

Question 1

How can rate of reaction be measured?

Answer 1

• measuring the volume of gas released in a reaction over time

Question 2

Why does rate of reaction increase with increasing temperature?

Answer 2

• molecules have greater KE
• more molecules have energy equal to or greater than Ea so can react
• more successful collisions per unit time

Question 3

How would you investigate how rare of reaction varies with temp.
Na2S2O3(aq) + 2HCl (aq) —> 2NaCl (aq) + SO2 (g) + S(s)

Answer 3

• this reaction produces a cloudy sulfur precipitate
• to measure rate, time how long it takes for cross underneath beaker to disappear, using a stopwatch
• repeat this at 5+ different temperatures and compare time taken

Question 4

What are some issues with that method?

Answer 4

• the disappeared cross is judged by eye and hence can be unreliable
• might be delayed reaction time with stop watch
• at low temps reaction may be too slow
• may not be enough precipitate for cross to disappear

Question 5

How could you analyse the data ?

Answer 5

• for a graph of the amount of sulfur against time, it would be a straight line at the beginning as the reaction has only just begun
• gradient of this straight section would be the rate of reaction
• compare the rate of reaction for each temperature

Question 6

What’s a control variable?

Answer 6

A variable kept constant throughout the whole experiment

Question 7

In this experiment, what variables will you control?

Answer 7

• concentrations of reactants of products
• volumes of reactants and products
• use the same beaker and cross underneath
• use the same person to decide when cross has disappeared

Question 8

How can we keep a substance at constant temperature?

Answer 8

Using a water bath