You have two bottles, each of which contains a white, crystalline substance. Your lab director tells you that one contains lactose and the other sucrose. Your job is to determine which bottle contains which sugar. Which procedure would you use?
Select one:
A. Test both for solubility in water. Sucrose is very soluble; lactose is only minimally soluble.
B. Dissolve each in water and record the pH. Lactose is far more acidic than sucrose.
C. React each with bromine (Br2) water. Only sucrose will react.
D. Test for the ability to reduce Ag+. Only lactose will react

To identify the substances found in the bottles, the procedure that would be done is Test for the ability to reduce Ag⁺. Only lactose will react.

Explanation:

Lactose is a disaccharide composed of glucose and galactose, considered a reducing sugar due to the carbonyl group in its structure.  To test the ability of lactose to reduce Ag⁺, Tollens reagent, which contains silver nitrate, is used.

The reaction that occurs reduces Ag, causes it to precipitate and forms a silver deposit, called a silver mirror.  This is the way to differentiate the lactose found in one tube and the sucrose found in the other.

Sucrosa is not a reducing sugar.

Learn more:

Reducing sugars link

sex cells are usually half's then they find another half and make a fertilize egg