Balancing Equations

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that in a closed system, the total mass of reactants must equal the total mass of products in a chemical reaction.

Front

What is a reactant in a chemical equation?

Back

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

Front

What is a product in a chemical equation?

Back

A product is a substance that is formed as a result of a chemical reaction, found on the right side of a chemical equation.

Front

What does it mean to balance a chemical equation?

Back

Balancing a chemical equation means ensuring that the number of atoms of each element is the same on both sides of the equation.

Front

What is a coefficient in a chemical equation?

Back

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

Front

How do you determine the number of atoms in a compound?

Back

To determine the number of atoms in a compound, multiply the coefficient by the subscript of each element in the formula.

Front

What is the significance of subscripts in a chemical formula?

Back

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

Front

How many oxygen atoms are in 3 Ca(OH)2?

Back

There are 6 oxygen atoms in 3 Ca(OH)2 because each Ca(OH)2 has 2 oxygen atoms, and 3 times 2 equals 6.

Front

What is the balanced equation for the reaction of sodium and copper(II) sulfate?

Back

The balanced equation is 2 Na + CuSO4 → Na2SO4 + Cu.

Front

What is the purpose of balancing chemical equations?

Back

The purpose of balancing chemical equations is to obey the law of conservation of mass and accurately represent the quantities of reactants and products.