Final answer:
To use Benedict's solution on monosaccharide units, ensure the sugar is in a form that can react with Benedict's solution, wear goggles for safety, and apply heat after combining the monosaccharide solution with Benedict’s solution in a test tube.
Step-by-step explanation:
Before Benedict's solution can work on these monosaccharide units, you must have monosaccharides in a form that Benedict’s solution can react with. Benedict's test is used specifically for reducing sugars. Reducing sugars are those that have free aldehyde or ketone group in their structure, which are able to reduce the copper(II) ions in the Benedict's solution to copper(I) oxide, forming a brick-red precipitate. Monosaccharides may exist as a linear chain or in ring-shaped molecules, and in aqueous solutions, they predominantly exist in their cyclic form. In some cases, polysaccharides must be hydrolyzed into monosaccharides before the Benedict's test can be applied.
Here's a simple step-by-step guide on preparing a monosaccharide sample for Benedict's test:
Ensure that you are working with a monosaccharide or a reducing disaccharide in a liquid solution form.
Wear goggles to protect your eyes as you're working with chemicals.
Add the monosaccharide solution to a test tube.
Add 10 drops of Benedict's solution to the test tube containing the monosaccharide.
Heat the liquid for about 3 minutes in a water bath to facilitate the reaction.