British Sign Language Glossaries of Curriculum Terms

BSL Chemistry Glossary - Benedict's solution - Definition

Benedict's solution is used as a test for reducing sugars, by adding it we can find out if reducing sugars are present. If they are, the Benedict's solution will change colour. Let me show you. One of these test tubes in the beaker contains glucose and the other starch. I need to add some hot water to the beaker to start the reaction.

(2.04) Benedict's solution turns orange in the presence of a reducing sugar. With starch it shouldn't change colour; it should remain blue. Let's watch and see what happens as the hot water starts to heat things up.

(3.27) The contents of this test tube have changed colour which means it does contain the reducing sugars that are in glucose, fructose and maltose and that's why we see the colour change. In the other test tube there has been no colour change and that's because it has starch in it.

This is a good way of testing for reducing sugars, but there is another method using iodine solution so have a look back in the glossary.