Law of Conservation of Mass Review

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that in a closed system, mass is neither created nor destroyed during a chemical reaction. The total mass of reactants equals the total mass of products.

Front

If a reaction starts with 75g of reactants, how much should it produce?

Back

75g of products.

Front

In the reaction AB -> A + B, if AB has 12g and B has 5g, how much does A weigh?

Back

7g.

Front

What does it mean when we say matter can be transformed?

Back

It means that matter can change forms or states but cannot be created or destroyed.

Front

What is a subscript in a chemical formula?

Back

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

Front

In the reaction A + B -> C, if A is 5g and C is 9g, how much does B weigh?

Back

4g.

Front

What is a coefficient in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula to indicate how many molecules or moles of that substance are involved in the reaction.

Front

Can mass be created or destroyed in a chemical reaction?

Back

No, mass cannot be created or destroyed; it can only change forms.

Front

What is the total mass of products if the total mass of reactants is 100g?

Back

100g.

Front

What happens to the mass of reactants during a chemical reaction?

Back

The mass of reactants remains constant and equals the mass of the products.