A solution of I2 was standardized with ascorbic acid. Using a .1000 g sample of pure ascorbic acid, 25.32 mL of I2 were required to reach the starch end point. A. What is the molarity of the iodine solution? B. What is the titer of the iodine solution?
I've got answer to the first part of this question, but I don't know how to answer part B!
To calculate the titer of the iodine solution in this context, you need to understand the concept of titer. Titer is a measure of the concentration of a solution, specifically the concentration of a titrant. In this case, the titrant is the iodine solution (I2).
The titer is determined by the volume of titrant solution required to reach the end point of the titration with a known concentration of the analyte (ascorbic acid). In this case, the volume of iodine solution required to reach the starch end point is given as 25.32 mL.
To calculate the titer, follow these steps:
1. Determine the moles of ascorbic acid (analyte) used in the titration.
- The molar mass of ascorbic acid (C6H8O6) is 176.124 g/mol.
- Use the mass of the sample given (0.1000 g) and divide it by the molar mass to find the moles of ascorbic acid used.
2. Convert the moles of ascorbic acid to moles of iodine.
- From the balanced chemical equation for the reaction between iodine and ascorbic acid, you can see that the ratio of moles of iodine to moles of ascorbic acid is 1:1.
3. Calculate the moles of iodine solution used in the titration.
- Since the ratio of moles of iodine to moles of ascorbic acid is 1:1, the moles of iodine solution used is equal to the moles of ascorbic acid used.
4. Calculate the titer of the iodine solution.
- Divide the moles of iodine solution used by the volume of iodine solution used (25.32 mL converted to L) to get the molarity (titer) of the iodine solution.
Hope this helps! Let me know if you have any further questions.