Conservation of Mass (Crash Course & BrainPOP)

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction; it can only change forms.

Front

If you dissolve 20 grams of sugar in 100 grams of water, what is the total mass of the solution?

Back

120 grams.

Front

What type of change occurs when sugar dissolves in water?

Back

Physical change.

Front

What is a chemical reaction?

Back

A chemical reaction is the process in which two or more molecules interact to form one or more new substances.

Front

Why is the law of conservation of mass important in chemical reactions?

Back

It helps predict the amount of products in a reaction.

Front

What is the difference between a physical change and a chemical change?

Back

Physical changes alter appearance without changing composition and are often reversible; chemical changes create new substances and are usually irreversible.

Front

Can mass be lost or gained in a chemical reaction?

Back

No, according to the law of conservation of mass, mass is neither lost nor gained.

Front

What happens to the mass of substances during a physical change?

Back

The mass remains the same; it only changes form.

Front

Give an example of a physical change.

Back

Melting ice is an example of a physical change.

Front

Give an example of a chemical change.

Back

Burning wood is an example of a chemical change.