Question

A solution of sodium thiosulfate was standardized by dissolving 0.1110 g KIO3 in water, adding a large excess of KI, and acidifying with HCl. The liberated iodine required 40.64 mL of the thiosulfate solution to decolorize the blue starch/iodine complex. Calculate the molar concentration of the Na2S2O3. IO3- (aq) + I- (aq) ? I2 (s) I2 (s) + S2O3^2- (aq) ? I- (aq) + S4O6^2- (aq) MM: KIO3 = 214.00 Na2S2O3 = 158.11 I2 = 253.81

          A solution of sodium thiosulfate was standardized by dissolving 0.1110 g KIO3 in water, adding a large excess of KI, and acidifying with HCl. The liberated iodine required 40.64 mL of the thiosulfate solution to decolorize the blue starch/iodine complex. Calculate the molar concentration of the Na2S2O3.
IO3- (aq) + I- (aq) ? I2 (s)
I2 (s) + S2O3^2- (aq) ? I- (aq) + S4O6^2- (aq)
MM: KIO3 = 214.00
Na2S2O3 = 158.11
I2 = 253.81

A solution of sodium thiosulfate was standardized by dissolving 0.1110 g KIO3 in water, adding a large excess of KI, and acidifying with HCl. The liberated iodine required 40.64 mL of the thiosulfate solution to decolorize the blue starch/iodine complex. Calculate the molar concentration of the Na2S2O3.
IO3- (aq) + I- (aq) ? I2 (s)
I2 (s) + S2O3^2- (aq) ? I- (aq) + S4O6^2- (aq)
MM: KIO3 = 214.00
Na2S2O3 = 158.11
I2 = 253.81

Added by Jessica W.

Chemistry: Structure and Properties

Nivaldo Tro 2nd Edition

Instant Answer

Solved by Expert David Collins

12/05/2021

Step 1

- Mass of KIO3 = 0.1110 g - Volume of Na2S2O3 solution used = 40.64 mL = 0.04064 L - Molar Mass (MM) of KIO3 = 214.00 g/mol - Molar Mass of Na2S2O3 = 158.11 g/mol - Molar Mass of I2 = 253.81 g/mol Show more…

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A solution of sodium thiosulfate was standardized by dissolving 0.1110 g KIO3 in water, adding a large excess of KI, and acidifying with HCl. The liberated iodine required 40.64 mL of the thiosulfate solution to decolorize the blue starch/iodine complex. Calculate the molar concentration of the Na2S2O3. IO3- (aq) + I- (aq) → I2 (s) I2 (s) + S2O3^2- (aq) → I- (aq) + S4O6^2- (aq) MM: KIO3 = 214.00 Na2S2O3 = 158.11 I2 = 253.81