Front

What is the Law of Conservation of Mass?

Back

Matter cannot be gained or lost in a chemical reaction.

Front

What is a balanced chemical equation?

Back

A chemical equation where the number of atoms for each element is the same on both sides.

Front

What does a coefficient in a chemical equation represent?

Back

The number of molecules or atoms of a substance in a reaction.

Front

What is a subscript in a chemical formula?

Back

A small number written after an element symbol indicating the number of atoms of that element in a molecule.

Front

How do you balance the equation: H2 + Cl2 -> HCl?

Back

2H2 + Cl2 -> 2HCl.

Front

What is the first step in balancing a chemical equation?

Back

Write the unbalanced equation.

Front

What is the purpose of balancing chemical equations?

Back

To ensure that the same number of each type of atom is present on both sides of the equation.

Front

How many HCl molecules are needed to balance: Mg + __HCl -> MgCl2 + H2?

Back

2 HCl.

Front

What is the difference between a coefficient and a subscript?

Back

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

Front

What is the balanced form of the equation: Al + HCl -> H2 + AlCl3?

Back

2Al + 6HCl -> 3H2 + 2AlCl3.