Mean titre of 0.2M sodium thiosulphate = 32.2 ml
1) Calculate number of moles of S2O32- which react in the titration
2)Calculate how many moles of I2 react with this amount of S2O3
3)How many Cu2+ ions are needed to liberate this amount of I2? Use this answer as the number of moles of Cu2+ ions in your 25cm3 aliquot of “coin solution”. How many moles of Cu2+ ions were in the 250cm3 of “coin solution”?
4) Knowing that Ar(Cu) = 63.5 – calculate the number of grams of copper in this “coin solution”.
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