A solution of sodium thiosulfate was standardized by dissolving 0.1668 g KIO3 (214.00 g/mol) in water,...

A solution of sodium thiosulfate was standardized by dissolving 0.1668 g KIO₃ (214.00 g/mol) in water, adding a large excess of KI, and acidifying with HCl. The liberated iodine required 22.11 mL of the thiosulfate solution to decolorize the blue starch/iodine complex. Calculate the molarity of the sodium thiosulfate solution.

Solutions

Expert Solution

IO₃^- (aq) + 8 I^- (aq)+ 6 H⁺ (aq) <------> 3I₃^- (aq) + 3 H₂O (l)

In acidic solutions tri iodide oxidizes thiosulfate totetrathionate.

I₃^- (aq) + 2S₂O₃^-2 (aq) <-----> 3I^- (aq) + S₄O₄^-2(aq)

The number of moles of KIO3 added = 0.1668 / 214.0g/mol

= 7.79 x 10^-4 mol

The number of moels of I₃^- generated from this solution = 3 x 7.79 x 10^-4

= 2.34 x 10^-3 mol

Thus the number of moles of thiosulfate = 2 x 2.34 x 10^-3

= 4.68 x 10^-3 mol

concentration of the thiosulfate solution = 4.68 x 10^-3 /0.02211 L

concentration of the thiosulfate = 0.212 M

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

A solution is made by dissolving 10.0 g of sodium chloride in 110.5 g of water...

A solution is made by dissolving 10.0 g of sodium chloride in 110.5 g of water at 25oC. The density of the solution is 1.021 g/mL 1.What is the osmotic pressure of this solution? 2.What is the boiling point of this solution? 3.What is the freezing point of this solution?

a solution is made by dissolving 0.131 mol of sugar,C12H22O11, in 175 g of water. the...

a solution is made by dissolving 0.131 mol of sugar,C12H22O11, in 175 g of water. the amount by which the vapor pressure is lowered is? (The vapor pressure of water is 23.76 mm Hg at 25 degrees Celcius. please explain: thank you! Answers: A) 23.00 mm Hg B) 0.316 mm Hg C) 17.8 mm Hg D) 3.11 mm Hg E) 1.33 mm Hg

Calculate the concentration of an iodate solution prepared by dissolving 1.9853 g of KIO3 and diluting...

Calculate the concentration of an iodate solution prepared by dissolving 1.9853 g of KIO3 and diluting to 500 mL with distilled water in a volumetric flask. A 25 mL aliquot of a 0.0195 M KIO3 solution is added to a flask containing 2 g of KI and 10 mL of 0.5 M H2SO4. The resulting solution is titrated to a starch endpoint with 34.81 mL of the thiosulfate solution. Calculate the concentration of the thiosulfate solution. How will you know...

(a) Potassium iodate solution was prepared by dissolving 1.022 g of KIO3 (FM 214.00) in a...

(a) Potassium iodate solution was prepared by dissolving 1.022 g of KIO3 (FM 214.00) in a 500 mL volumetric flask. Then 50.00 mL of the solution was pipetted into a flask and treated with excess KI (2 g) and acid (10 mL of 0.5 M H2SO4). How many millimoles of I3− are created by the reaction b) The triiodide from part (a) reacted with 37.57 mL of Na2S2O3 solution. What is the concentration of the Na2S2O3 solution? (c) A 1.223...

You form a solution by dissolving 15.39 grams of sodium chloride (molar mass = 58.44 g/mol)...

You form a solution by dissolving 15.39 grams of sodium chloride (molar mass = 58.44 g/mol) into 163.7 grams of water (molar mass = 18.02 g/mol). The total volume of the solution is 180.1 mL. Part #1: What is the molarity of sodium chloride in this solution? Part #2: What is the mass percent of sodium chloride in this solution? Part #3: What is the mole fraction of sodium chloride in this solution? Part #4: What is the molality of...

A buffer solution was prepared by dissolving 4.00 grams of sodium propanate (NaCH3CH2CO2, FM 96.06 g/mol)...

A buffer solution was prepared by dissolving 4.00 grams of sodium propanate (NaCH3CH2CO2, FM 96.06 g/mol) in a solution containing 0.100 moles of propanoic acid (CH3CH2CO2H) and diluting the mixture to 1.00 L. pKa for propanoic acid is 4.874. (a) To this solution was added 5.00mL of 1.00 M HCl. Calculate the pH of the resulting solution. (b) To this solution was added 5.00mL of 1.00 M NaOH. Calculate the pH of the resulting solution.

A solution is prepared by dissolving 11.6 g of a mixture of sodium carbonate and sodium...

A solution is prepared by dissolving 11.6 g of a mixture of sodium carbonate and sodium bicarbonate in 1.00 L of water. A 300.0 cm3sample of the solution is then treated with excess HNO3 and boiled to remove all the dissolved gas. A total of 0.940 L of dry CO2 is collected at 298 K and 0.972 atm. 1. Find the molarity of the carbonate in the solution. 2. Find the molarity of the bicarbonate in the solution.

A solution is made by a dissolving 16.8 g of sodium fluoride , NaF , in...

A solution is made by a dissolving 16.8 g of sodium fluoride , NaF , in enough water to make exactly 500.ml of solution . Calculate the molarity of each species: NaF, Na+ and F-.

A solution is made by dissolving 45.5 g of sodium phosphate in 265 g of ethanol....

A solution is made by dissolving 45.5 g of sodium phosphate in 265 g of ethanol. The resulting solution has a volume of 225 mL. Using the above information, values found in Table 14.6, a vapor pressure of 5.87×10−2 atm at 20 oC, and the theoretical van’t Hoff factor, determine the following for the resulting solution: A. M of Na3PO4 B. m of Na3PO4 C. Freezing point in oC D. Boiling point in oC E. Osmatic pressure at 20 oC...

Calculate the concentration of the standardized thiosulfate solution. The following are the steps and the concentration...

Calculate the concentration of the standardized thiosulfate solution. The following are the steps and the concentration of my KIO3 was 0.0114 and the weighed mass of Na2S2O3 was 1.719 g Weigh about 1.7 g Na2S2O3  5H2O, and transfer it to a 4 oz glass storage bottle. Add 100 mL (graduated cylinder) of room-temperature DI water, which has beenbubbled extensively with nitrogen, and which contains 100 mg /liter Na2CO3. Mix thoroughly and add 1 drop of chloroform to prevent bacterial...

Subjects