RP3- Rate of Reaction Flashcards
How could values for each reaction be obtained?
Measure the temperature at the start and end of the reaction and find
the mean/average
What should all graphs contain?
- suitable scale
- correct points
- line of best fit
What are 2 ways rate of reaction can be measured?
- initial rates
- continuous monitoring
How would you investigate how the rate of reaction would change with temp?
- reaction between sodium thiosulfate and HCl
- cloudy precipitate
- measure time taken for cross underneath beaker to disappear
- repeat at different temps
Why is the method using an obscured cross inaccurate?
- subjective
- delayed reaction time
- too slow
What control variables would you have if you were measuring the effect of temperature on the rate of reaction?
- concentrations of reactants and products
- volumes of reactants and products
- use same beaker and cross as well as end point
How do you maintain and control temperature?
water baths
Outline a method to find out the effect of temperature on initial rate of reaction
- put acid into container on top of a laminated cross
- use water bath to maintain desired temperature
- add second reactant and start timing
- record time for cross to disappear
- control variables and repeat at different temperatures
- 1/t as measure of rate
- plot graph
Explain the the reaction between hydrochloric acid and sodium
thiosulfate should only be carried out on a small scale
Toxic sulfur dioxide is a product
Explain how the reaction between hydrochloric acid and sodium
thiosulfate can be monitored
The reaction produces a sulfur precipitate. Time how long it takes for the precipitate to
obscure a cross. Rate = 1 / time
Why is the time taken recorded to the nearest second and not 0.01 seconds?
as exact moment cross obscured is difficult to determine
Why are temperatures between 1-10C not tested?
reaction too slow at these temperatures
