Accurately weigh 0.9-1.1 g into a 200 mL beaker.

Dissolve the KIO3 in a small amount of distilled water.

Quantitatively transfer, with rinsing, to a 500 mL volumetric flask.

Dilute to the calibration mark and shake well.

Rinse the buret several times with small portions of the thiosulfate solution.
Fill the buret with the thiosulfate titrant solution.

Add with a pipet a 50.00 mL aliquot of the KIO3 solution to a 250 mL Erlenmeyer flask. This is the titration flask.

Add ca. 2 g of KI to the titration flask and swirl to dissolve.

Add, with rapid mixing, 5 mL of dilute H2SO4.

Titrate immediately with thiosulfate solution.

Pre-lab calculation: Calculate the approximate amount of titrant that will be required for this titration, using reasonable assumptions.

IO3^- + 5I^- + 6H^+ ==> 3I2 + 3H2O

Then you titrate the liberated I2 with the thiosulfate.
2S2O3^2- + I2 ==> 2I^- + S4O6^2-

How much KIO3 did you weigh out? It was supposed to be weighed accurately but weigh out about 1 g. I will assume you weighed out exactly 1.00 g KIO3. You placed in a 250 mL volumetric flask and transferred exactly 50 mL into the titration flask so the amount of KIO3 in the titration is 1 g x (50/250) or 0.2000 g.
mols KIO3 in 0.2g = g/molar mass KIO3 or about 0.00093 mols KIO3
Convert that to mols I2 released when adding the KI. Look at the equation and that will be mols KIO3 x 3 or about 0.0028.

Then the titration step. Look at the coefficients in the 2S2O3^2- + I2 equation. 0.0028 mols I2 will take twice that or 0.0056 mols thiosulfate.
M thiosulfate = mols/L or rearrange to L thiosulfate = mols/M = 0.0056/M
You must know the M of the thiosulfate; divide that into the 0.0056 to find L. Convert to mL. If the thiosulfate is about 0.1M it will take about 56 mL.

To calculate the approximate amount of titrant required for this titration, you need to make a few assumptions based on the given information.

First, you need to determine the molarity (concentration) of the thiosulfate titrant solution. This can be done by performing a standardization titration using a known concentration of iodine. However, since this information is not given in the instructions, we will assume that the thiosulfate solution is already standardized and its concentration is known.

Assuming the molarity of the thiosulfate titrant solution is 'M', and the volume of the aliquot of the KIO3 solution is 50.00 mL, we can use the balanced chemical equation for the reaction between KIO3 and thiosulfate (S2O3) to calculate the approximate amount of titrant required.

The balanced equation is:

2S2O3^(2-) + I2 -> S4O6^(2-) + 2I^-

From the equation, we can see that each mole of thiosulfate reacts with 1 mole of iodine (I2). Therefore, the number of moles of thiosulfate needed to react with the iodine formed from the KIO3 is equal to the number of moles of iodine present.

Since the iodine formed is equivalent to the iodine in the KIO3 solution, we can use the molarity of KIO3 and its volume to determine the number of moles of iodine:

moles of iodine = Molarity of KIO3 * Volume of KIO3 solution (in liters)

Next, we determine the volume of thiosulfate solution needed to react with these moles of iodine. Based on the chemical equation, we know that each mole of thiosulfate reacts with 1 mole of iodine. Therefore, the volume of thiosulfate solution required is:

Volume of thiosulfate solution (in liters) = moles of iodine / Molarity of thiosulfate solution

Now that you have the volume of thiosulfate solution required, you can convert it to milliliters and perform the necessary calculations.

Note: The instructions do not provide the molarity of the KIO3 solution, so you may need to assume a reasonable value based on your knowledge or consult additional information provided to you.