Sodium thiosulfate, Na₂S₂O₃, is used in photographic film developing. Th e amount of Na₂S₂O₃ in a solution can be determined by a titration with I₂, according to the following equation:

Calculate the concentration of the Na₂S₂O₃ solution if 30.30 mL of a 0.1120 M I₂ solution reacts completely with a 100.0-mL sample of the Na₂S₂O₃ solution. In the actual experiment, excess KI is added to solubilize the I2, but it is not part of the chemical change.

Transcribed Image Text:

2Na2S₂O3(aq) + 1₂(aq) → Na₂S4O6(aq) + 2Nal(aq)