Iodine deficiency can cause a goiter, which is an enlargement of the thyroid gland. You are sent to Pakistan to make field measurements of the concentration of iodide (I-) that is present in groundwater.
Procedure:
(a) Oxidize I- in sample to I2 with potassium peroxymonosulfate.
(b) Add the dye leuco crystal violet, which reacts with I2 to form a violet color, which absorbs at 590 nm.
Results:
(a) A standard solution containing 3.5x10-6 M solution of I- displayed an absorbance of0.20 at 590 nm.
(b) A sample of groundwater from Pakistan gave an absorbance of 0.140. What is the concentration of I- in the groundwater?