state the each purpose of each reagent in the mixture. is it an oxidizing agent,
ID: 550288 • Letter: S
Question
state the each purpose of each reagent in the mixture. is it an oxidizing agent, reducting agent, chromophore, etc?
this is analysis of iron in a vitamin tablet lab
and I have no idea..
Procedure for preparation of standard solutions 1. Obtain 6 clean 100 mL volumetric flasks. 2. Obtain 50 mL of standard Fe solution in a small beaker. Use 5 mL of solution to rinse your buret and then fill the buret with the remaining solution. Dispense 10.00 mL of standard Fe solution into a beaker and measure the pH with pH paper. Add the sodium citrate solution 1 drop at a time until a pH of 3.5 is reached (use pH paper, go to a red-orange color). Count the drops needed. (It will require about 30 drops.) Dispense a fresh 10.00-mL aliquot of Fe standard into a 100-mL volumetric flask and add the same number of drops of citrate solution as required in Step 1. Add 2.00 mL of hydroquinone solution and 3.00 mL of o-phenanthroline solution dilute to the mark with water, and mix well. In the remaining five 100 mL volumetric flasks, prepare solutions with 0 (blank), 2, 4, 6 and 8 mL of Fe standard plus 2.00 mL of hydroquinone solution and 3.00 mL of o-phenanthroline solution. Add sodium citrate solution in proportion to the volume of Fe solution (if 10 mL of Fe requires 30 drops of citrate solution, 2 mL of Fe requires 6 drops of citrate solution). Dilute to the mark with d.i. water. You should have a series of 6 standard solutions that increase in color intensity. 3. 4. 5.Explanation / Answer
sodium citrate is used as the buffer maintaing a constant pH of 3.5.
O- phenanthroline is used as the colorimetric agent where the delocalised phenanthrene rings act as chromophores.
The hydroquinone is used as the water soluble reducing agent.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.