Which test is used to identify the presence of sugars in a sample?

The presence of sugars in a sample is identified using Benedict's Test. This test is based on the principle that reducing sugars, such as glucose and fructose, can reduce copper(II) ions to copper(I) oxide, resulting in a color change that indicates the presence of these sugars. When the test solution is heated with Benedict's reagent, which contains copper sulfate, a color change occurs if reducing sugars are present, typically shifting from blue to green, yellow, or red depending on the concentration of the sugar.

The other tests listed serve different purposes:

• The Iodine Test is utilized to detect starch by turning blue-black when starch is present.
• The Biuret Test is used for detecting proteins; it turns violet in the presence of peptide bonds.
• The Litmus Test is a general acid-base indicator that changes color in response to pH but does not specifically identify sugars.

Thus, Benedict's Test is the appropriate method for identifying sugars due to its specific interaction with reducing sugars and the resulting visual change that signifies their presence.