In the Ferric Reduction method, what are the colors of the reagents before and after reaction with glucose?

In the Ferric Reduction method, what are the colors of the reagents before and after reaction with glucose?

• A. Yellow-orange (reagent) and colorless (product)
• B. Blue (reagent) and green (product)
• C. Red (reagent) and colorless (product)
• D. Colorless (reagent) and yellow-orange (product)

Answer: (A)

In the Ferric Reduction Method, reducing sugars like glucose donate electrons to ferric ions (Fe3+), converting them to ferrous ions (Fe2+). The ferric complex in the reagent has a yellow-orange color, so the solution appears yellow-orange before the reaction. When glucose reduces Fe3+ to Fe2+, the colored ferric form is removed and the product is colorless, so the solution decolorizes. Thus the reagent is yellow-orange initially and becomes colorless after reacting with glucose.

In the Ferric Reduction Method, reducing sugars like glucose donate electrons to ferric ions (Fe3+), converting them to ferrous ions (Fe2+). The ferric complex in the reagent has a yellow-orange color, so the solution appears yellow-orange before the reaction. When glucose reduces Fe3+ to Fe2+, the colored ferric form is removed and the product is colorless, so the solution decolorizes. Thus the reagent is yellow-orange initially and becomes colorless after reacting with glucose.