Balancing Chemical Equations

Front

What is a balanced chemical equation?

Back

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

Front

What are coefficients in a chemical equation?

Back

Coefficients are the numbers placed before compounds in a chemical equation to indicate how many molecules or moles of that substance are involved in the reaction.

Front

What are subscripts in a chemical formula?

Back

Subscripts are the small numbers written after an element in a chemical formula that indicate the number of atoms of that element in a molecule.

Front

Why can't subscripts be changed when balancing equations?

Back

Changing subscripts alters the identity of the substance, which can change the chemical properties and the reaction itself.

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

How do you identify an unbalanced equation?

Back

An unbalanced equation will have a different number of atoms of one or more elements on the reactant side compared to the product side.

Front

What is the first step in balancing a chemical equation?

Back

The first step is to write down the number of atoms of each element present in the reactants and products.

Front

What does it mean to balance an equation?

Back

To balance an equation means to adjust the coefficients so that the number of atoms for each element is the same on both sides of the equation.

Front

What is the balanced equation for the reaction of aluminum and hydrochloric acid?

Back

2Al + 6HCl → 3H2 + 2AlCl3.

Front

What happens to the mass of reactants when they produce gas?

Back

The mass of the products, including the gas, will equal the mass of the reactants if the gas is contained.