Law of conservation of mass

Front

What is the Law of Conservation of Mass?

Back

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

Front

What does it mean for a chemical reaction to be balanced?

Back

A chemical reaction is balanced when both sides have the same number of atoms for each element involved.

Front

If 200 grams of ice melts in 900 grams of water, what is the total mass of the water after the ice has melted?

Back

1,100 grams.

Front

What are reactants in a chemical reaction?

Back

Reactants are the starting substances that undergo a chemical change in a reaction.

Front

In the reaction 2Mg + O2 → 2MgO, what are the reactants?

Back

Mg (magnesium) and O2 (oxygen).

Front

Define a molecule.

Back

A molecule is a group of atoms bonded together.

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

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

If 24 g of magnesium reacts with 38 g of fluorine, what is the mass of magnesium fluoride produced?

Back

62 grams.

Front

What is the difference between a reactant and a product?

Back

Reactants are substances that start a chemical reaction, while products are the substances formed as a result of the reaction.