Sodium Thiosulphate Essay, Research Paper

In this investigation I will change the concentration

of the sodium thiosulphate by adding water in each case to make it more dilute

but when adding the water it must bring the volume up to 10cm? everytime to make it a fair test.?????????????????????????? ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Dependant

variable.?????????????????????????????????????????????????????????????????????????????

I will measure the time taken for the cross to disappear,as it will show

whether the rate of reaction has increased or decreased. The rate of reaction

has increased if the time has decreased as the reaction has occurred alot

quicker so therefore the time taken is alot less.The rate of reaction has

decreased if the time has increased as the reaction is alot slower and

therefore the time taken is alot longer.???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Controlled

variables.????????????????????????????????????

?????????????????????????????????????I will keep: the

same volume of hydrochloric acid.????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

????????????????????????????????????????????????????????the same

reaction volume(total volume 20 cm ).?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

???????????????????????????????????????????????????????the same

size of the cross.?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

??????????????????????????????????????????????????????the same size

conical flask.?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

?????????????????????????????????????????????????????the same

amount of swirling of the solution.??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

????????????????????????????????????????????also the same peron

will be timing the stopwatch.??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

????????????????????????????????????????????and the same person

will be judging how long it takes??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

????????????????????????????????????????????for the cross to become

invisible.?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

????The controlled variables are

to make the experiment a fair test.???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

Note:The total volume is always the same,water must be added??? ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????to

the solution to bring it up to 20 cm .????????????? ?????????????????????????????????????????????????