What is the equivalent weight of sulphur in

S~(S2O3)2- +(S)2-

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The equivalent weight is the gram molecular weight divided by the number of electrons lost or gained by each molecule; e.g., potassium permanganate (KMnO4) in acid solution, 158.038/5 g; potassium dichromate (K2Cr2O7), 294.192/6 g; and sodium thiosulfate (Na2S2O3·5H2O), 248.1828/1 g.
In case of Sodium Thiosulfate the reation proceeds as under:


I2 + 2 Na2S2O3 → Na2S4O6 + 2 NaI


2 Na2S2O3 ≡ I2 ≡ Cl2 ≡ 2 e
Hence Na2S2O3 ≡ 1 e
Thus Molecular weight devded by 1 is the equivalent weight & hence both have same value

Dear Student

The equivalent weight is the gram molecular weight divided by the number of electrons lost or gained by each molecule
e.g., potassium permanganate (KMnO₄) in acid solution, 158.038/5 g;
potassium dichromate (K₂Cr₂O₇), 294.192/6 g;
and sodium thiosulfate (Na₂S₂O₃·5H₂O), 248.1828/1 g.
In case of Sodium Thiosulfate the reation proceeds as under:
I₂ + 2 Na₂S₂O₃ → Na₂S₄O₆ + 2 NaI

2 Na₂S₂O₃ ≡ I₂ ≡ Cl₂ ≡ 2 e
Hence Na₂S₂O₃ ≡ 1 e
Thus Molecular weight divded by 1 is the equivalent weight & hence both have same value.

I hope this answer will help you.
Thanks & Regards
Yash Chourasiya