Explanation: Like Algebra the Coefficient is the number in front of the variable terms. In Chemistry the coefficient is the number in front of the formula. The coefficient tells us how many molecules of a given formula are present.

oxygen form two molecules of water. • Another example: 2Al2O3 → 4Al + 3O2. – Two formula units Al2O3 form four atoms Al and three. molecules of oxygen. #2.

When you balance a chemical equation, you change coefficients. You never change subscripts. A coefficient is a whole number multiplier. To balance a chemical equation, you add these whole number multipliers (coefficients) to make sure that there are the same number of atoms on each side of the arrow.

It is usually an integer that is multiplied by the variable next to it. The variables which do not have a number with them are assumed to be having 1 as their coefficient. For example, in the expression 3x, 3 is the coefficient but in the expression x2 + 3, 1 is the coefficient of x2.

We will take the given equation: Al + O2 –> Al2O3. We can see that this is not balanced – there is 1 aluminum on the reactant side and 2 on the product side, and there are 2 oxygens on the reactant side and 3 on the product side. How will we balance it? Finally we have a balanced equation: 4Al + 3O2 –> 2Al2O3 .

A chemical equation consists of the chemical formulas of the reactants (on the left) and the products (on the right). The two are separated by an arrow symbol (“→” usually read aloud as “yields”). Each individual substance’s chemical formula is separated from others by a plus sign.