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Help to draw a half-life graph please??

Hi all,

I carried out a titration of 0.1moldm-3 sodium thiosulphate into Hydrogen Peroxide and I have to draw a graph plotting moles of H2O2 over time(s). The ratio of moles Sodium thiosulphate : H2O2 is 2:1, and the volume of titration corresponds to the volume of H2O2 left at each stage of the reaction. I have problems drawing it though :s-smilie::s-smilie: because I have to extrapolate the curve to t=0 and don't know what point it would be. Plus what range should the graph have on the y-axis??

Titre: Moles of sodium thiosulphate
60seconds - 6.2 cm3 0.1 x 0.0062dm3 = 6.2 x 10-4
120seconds - 4.6 cm3 0.1 x 0.0046dm3 = 4.6 x 10-4
180seconds - 3.4 cm3 0.1 x 0.0034dm3 = 3.4 x 10-4
240seconds - 2.5 cm3 0.1 x 0.0025dm3 = 2.5 x 10-4
300seconds - 1.6 cm3 0.1 x 0.0016dm3 = 1.6 x 10-4

Moles of H2O2
6.2 x 10-4 /2 = 3.1 x 10-4
4.6 x 10-4 /2 = 2.3 x 10-4
3.4 x 10-4 /2 = 1.7 x 10-4
2.5 x 10-4 /2 = 1.25 x 10-4
1.6 x 10-4 /2 = 0.8 x 10-4

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