CPAC A6: clock reaction

Question 1

purpose of clock reaction

Answer 1

• time to measure a certain concentration is reached (eg starch goes blue black to show iodine is produced)
• initial rate can be calculated

Question 2

method:

Answer 2

• add volumes where in each experimetn conc of one is changed and rest are constant
• combine reactant and start stop clock
• measure time for blue black colour to appear and record. calculate rate (proprtional to 1/time)
• repeat

Question 3

largest percentag error comes from

Answer 3

high concentrations with the shortest times

Question 4

calculating order graphically when only ONE reactant conc is measured

Answer 4

rate = k (x)^n
Log rate = log k + nlogx
- log x (x axis)
- log rate (y axis)
- log k = y intercept
- GRADIENT = N