We all know that Benedict's Solution shows a quick chemical detection test for sugar. It shows the redox reaction between sugar and copper cations in an alkaline solution.
But did you know you can make your own Benedict's Solution with some everyday lab items?
What are the ingredients of Benedict's Solution?
To make 100ml of Benedict's solution, you will need
- 17.0g Trisodium Citrate Dihydrate
- 10g Anhydrous Sodium Carbonate
- 1.74g Copper(II)Sulfate-5-Water
- 100ml water
For the samples
- Sucrose solution
- Glucose solution
- Hydrolysed sucrose solution
- Mixture of syrup with lemon and lime cordial
Equipment needed to make Benedict's Solution
- 250ml beaker
- 5 test tubes
- Test tube stand
- 5L water bath
- Magnetic stirrer
- Measuring cylinder
- Magnetic stir bar
How to make your own Benedict's Solution
- Pour 60ml of water into beaker, place on magnetic stirrer and switch on.
- Add 10g of Anhydrous Sodium Carbonate and continue stirring until the solid dissolves.
- Add 17.0g of Trisodium Citrate-2-Water and 1.74g of Copper(II) Sulfate-5-Water to the Sodium Carbonate Solution. Continue stirring to dissolve warming if necessary. Allow to cool to room temperature.
- Pour the solution into a suitable measuring cylinder and make up to 100ml
- Prepare five samples in 5 test tubes. The first sample is water. The second sample is sucrose solution. The third sample is glucose solution. The fourth sample is hydrolysed sucrose solution, which can be obtained by heating a mixture with hydrochloric acid and sucrose, followed by neutralisation with soda. The fifth sample is a mixture of syrup with lemon and lime cordial.
- Heat the samples using a water bath.
- Observe the change in colour of different solutions which will show different concentrations of sugars
What does Benedict’s Solution show and why is it important?
As we become more aware of the risks of a high sugar intake in our diets, Benedict's Solution is a great for demonstrating the different sugar content in our food and drink. Sugar is contained in a lot of foodstuffs, even in food we would consider savoury.
There are many different types of sugar, but Benedict's Test looks for sucrose, glucose and fructose.
How it works
The water is your control sample.
The second sample, sucrose, is a disaccharide made up of glucose and fructose sugars. It occurs naturally in plants and is typically in the form of refined (table) sugar. Our bodies break down the sucrose into glucose and fructose through enzymes in our mouths and mostly in our small intestines
Glucose, the third sample, is the sugar used by our bodies to make energy. It supplies almost all the energy needed by our brains, along with oxygen. Excess glucose is converted to glycogen, stored in our liver and muscles, ready for when we need a quick burst of energy. But the presence of glucose increases the amount of fructose absorbed, which then stimulates the release of insulin.
The hydrolysed sucrose solution, sample four, shows the chemical reaction of the sucrose separating into glucose and fructose. It contains all three sugars.
The final sample of syrup with lemon and lime cordial is fructose. The naturally occurring sugar in fruit. The fructose can be converted by our bodies to glucose. But the excess fructose is stored as fat and can lead to problems such as obesity.
The Benedict’s Solution test therefore can be incorporated into wider discussions around the uses and harmful effects of sugars on the human body.
Need a hand with making your own Benedict’s Solution?
The Philip Harris specialist team are here to help with any technical questions you have about setting up experiments, including making your own Benedict’s Solution. Call them on 0345 120 4521 or e-mail email@example.com.