Question

When you heat Benedict's solution with a) 10M glucose, b) 10M starch, c) water, what will the color turn?

1) Blue
2) Red
3) Yellow
4) No change in color

Answer 1

When heating Benedict's solution with 10M glucose, it is expected to turn brick red due to the high concentration of reducing sugar. With 10M starch, no color change will occur as starch is not a reducing sugar. Water will not change the color of Benedict's solution as it contains no reducing sugars.

Step-by-step explanation:

When heating Benedict's solution with different substances, the color change serves as an indicator of the presence of reducing sugars.

• a) 10M glucose - Benedict's solution will turn from blue to green, yellow, orange, or brick red, depending on the concentration of glucose. For a 10M solution, which is highly concentrated, the expected color would be a brick red precipitate.
• b) 10M starch - No color change should be expected because starch is not a reducing sugar. The solution will remain blue.
• c) Water - As water does not contain reducing sugars, there will be no change in color; the Benedict's solution remains blue.

Always remember to wear goggles in the laboratory when working with chemicals and heat.