Karen is working with an unknown organic substance. she mixes a sample of the substance with benedict's solution and heats it. the mixture changes from blue to a orange/red color. based on the test results, karen can conclude that the unknown substance is a

Carbohydrates (sugars)

Benedict’s Test used to test for carbohydrates (sugars). The Benedict’s test determines reducing sugars, which exhibit free ketone or aldehyde functional groups.  When the reducing sugars are heated with Benedicts reagent a reduction reaction changes the color of the reagent from green to rusty brown, orange or red depending upon the type of sugar.