4.3 Balancing Equations

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 atoms of that substance are involved in the reaction.

Front

What does the principle of conservation of mass state?

Back

The principle of conservation of mass states that matter is not created or destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

How do you balance a chemical equation?

Back

To balance a chemical equation, adjust the coefficients of the reactants and products to ensure that the number of atoms of each element is the same on both sides of the equation.

Front

What is a reactant in a chemical reaction?

Back

A reactant is a substance that undergoes a change during a chemical reaction, found on the left side of the equation.

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, found on the right side of the equation.

Front

What does it mean if a chemical equation is balanced?

Back

A balanced chemical equation has the same number of each type of atom on both sides, indicating that mass is conserved.

Front

How many atoms of aluminum are in the equation 4Al + 3O2 → 2Al2O3?

Back

There are 4 atoms of aluminum on the left side and 4 atoms on the right side, so the equation is balanced for aluminum.

Front

What is the role of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of an element in a molecule; for example, in H2O, the '2' indicates there are two hydrogen atoms.

Front

What is the difference between a reactant and a product?

Back

Reactants are the starting materials in a chemical reaction, while products are the substances formed as a result of the reaction.

Front

What does it mean to say that a reaction has a yield?

Back

Yield refers to the amount of product formed in a chemical reaction, often expressed as a percentage of the theoretical maximum.