Balancing Equations

Front

What is the purpose of balancing chemical equations?

Back

To ensure that the number of atoms of each element is the same on both sides of the equation, adhering to the Law of Conservation of Mass.

Front

What is a coefficient in a chemical equation?

Back

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 does the Law of Conservation of Mass state?

Back

Matter cannot be gained or lost in a chemical reaction.

Front

How do you determine if a chemical equation is balanced?

Back

By counting the number of atoms of each element on both sides of the equation and ensuring they are equal.

Front

What is the balanced equation for the reaction of PCl5 and H2O?

Back

PCl5 + 4 H2O → 5 HCl + H3PO4.

Front

What is the balanced equation for the reaction of Al and FeO?

Back

2 Al + 2 FeO → Al2O3 + 2 Fe.

Front

What is the difference between a subscript and a coefficient?

Back

A subscript indicates the number of atoms in a molecule, while a coefficient indicates the number of molecules.

Front

What happens if a chemical equation is not balanced?

Back

It does not accurately represent the conservation of mass and the actual quantities of reactants and products.

Front

What is the first step in balancing a chemical equation?

Back

Identify the number of atoms of each element in the reactants and products.

Front

Can you change the subscripts when balancing equations?

Back

No, changing subscripts alters the identity of the substance; only coefficients can be changed.