Chemical Changes and Law of Conservation of Mass

Front

Molecule

Back

A group of atoms bonded together.

Front

How many Oxygen atoms are in 4H₂O₂?

Back

8

Front

In a reaction A + B ----> C, reactant A has 5g and product C has 9g. How many grams does reactant B should have?

Back

4g

Front

Since gases weigh nothing, when they are produced in a reaction they do not have to be accounted for. True or False?

Back

False

Front

When CaCO₃ is heated, it forms CaO and CO₂. What happens to the mass of the products?

Back

The sum of the products’ masses equals the mass of the CaCO₃.

Front

What is the Law of Conservation of Mass?

Back

Mass is neither created nor destroyed in a chemical reaction.

Front

What is a reactant?

Back

A substance that undergoes change during a chemical reaction.

Front

What is a product?

Back

A substance that is formed as a result of a chemical reaction.

Front

What is a coefficient in a chemical equation?

Back

A number placed in front of a chemical formula to indicate how many molecules are involved.

Front

What is a subscript in a chemical formula?

Back

A number written below and to the right of a chemical symbol indicating the number of atoms of that element in a molecule.