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?

Answer 1

M = moles/L.
moles ascorbic acid = grams/molar mass.
Plug in moles and L and solve for M.

The "old" definition (meaning years ago when I was in school) titer was defined as N x milliequivalent weight. As far as I know, IUPAC doesn't recognize equivalent weights or normality now; therefore, I don't know if the definition of titer has changed or not. I looked in two or three modern texts and did not find the term; in fact, I had to go back to an old quant book published in 1952 to find it in the appendix, along with a very good description in the text.