Law of conservation of mass

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction; it can only be transformed or changed from one form to another.

Front

What happens to the total mass of reactants and products in a chemical reaction?

Back

The total mass of the reactants before the reaction is equal to the total mass of the products after the reaction.

Front

In a chemical reaction, what are reactants?

Back

Reactants are the starting substances that undergo a chemical change to form products.

Front

In the reaction 2Mg + O2 ---> 2MgO, identify the reactants.

Back

The reactants are Magnesium (Mg) and Oxygen (O2).

Front

What is a product in a chemical reaction?

Back

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

Front

What does it mean to say that matter can be transformed?

Back

To say that matter can be transformed means that it can change from one form to another, such as from solid to liquid, or from reactants to products in a chemical reaction.

Front

If reactant A has 5g and product C has 9g, how much does reactant B weigh in the reaction A + B ---> C?

Back

Reactant B weighs 4g.

Front

What is the coefficient in a chemical equation?

Back

The 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

In the equation 3H2O, what does the coefficient 3 represent?

Back

The coefficient 3 indicates that there are three molecules of water (H2O) in the reaction.

Front

What is the significance of balancing a chemical equation?

Back

Balancing a chemical equation ensures that the number of atoms of each element is the same on both sides of the equation, reflecting the Law of Conservation of Mass.