Question

What do you understand by a pure substance? Is milk a pure substance?

Answer 1

Pure substances - The substances that are made up of only the same kind of units(atoms or molecules or compounds).

For example - all elements and compounds are pure substances.

Milk is not a pure substance, milk is a mixture.

Mixture - when two or more substances are mixed physically in any variable proportion in such a way that they retain their individual properties, such type of substance is called a mixture.

Why is milk a mixture?

• Milk contains proteins, fats, and carbohydrates all mixed in variable proportions.
• The components in milk are mixed and distributed uniformly so it is a homogeneous mixture.