Question

PLS HELP!

1. Explain why your solutions have a purple color after the iron reagent is added. Yes, the answer is because it is absorbing the other colors. What is absorbing the other colors?
2. Explain why the spectrophotometer is ‘blanked’ with the iron reagent. Why couldn’t deionized water be used?

Answer 1

Question 1

Fe(III) forms a chelate complex with salicylic acid which has purple color. therefore, when a solution is made either with salicylic acid or with aspirin having trae amount of salicylic acid in it, we see color formation in solution due to the resulting complex formed.

Question 2

The Fe(III) itself absorbs some light and gives an absorbance value for the solution. Therefore, it is necessary to blank the spectrophotometer with a Fe(III) solution prior to measurement of test solutions.