The Rate of Reaction between Thiosulphate and Hydrochloric Acid

The Rate of Reaction between Thiosulphate and Hydrochloric Acid

Equipment: pen, paper, 2 measuring cylinders, conical flasks, 2

beakers, HLC, Na2SO4, stop clock.

Method: What I am going to do is draw a cross on the paper with the

pen then get10cm3 of Na2SO4 and 50cm3 of HCL and put in separate

beakers. Then put the Na2SO4 in the conical flask, which is placed on

the cross on the paper. Then I will add the HCL to the Na2SO4 and

start the stop clock. I will stop the clock when I can not physically

see the cross any more.

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I will put the Na2SO4 in the conical flask first every time to keep

the test fair. The HCL is measured in strength by Ms the strongest I

will use is 1M. I will do the test 5 times and will weaken the acid by

adding water.

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The 5 tests I will do are going to be 0.2, 0.4, 0.6, 0.8 and 1M. If

you have 100cm3 of HCL at 1M, to make that a concentration of 0.8 you

need to take 20cm3 of HCL from that and replace it with 20cm3 of

water. To make it 0.6 from 1M, you will need to take 40cm3 of that HCL

and replace it with 40cm3 of water. I will do this for 0.4 and 0.2 but

I will half everything so it will still be fair. Also to make sure the

correct results are recorded I will do each test 3 times and take an

average of the 3. I will record the results by time taken for the

cross to disappear.

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I will keep the test fair by ensuring the following criteria are met,

goggles worn at all times of the experiment, take great care when

handling acid and glass, wash my hands if any acid is spilt.

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I will the test fair at all time by always, adding Thiosulphate

second, use the same amount of liquid, look at the cross from above at