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 is the law of conservation of mass?

Back

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction; it can only change forms.

Front

What does a coefficient in a chemical equation represent?

Back

A coefficient indicates the number of molecules or moles of a substance involved in a chemical reaction.

Front

How do you determine the coefficient needed to balance an equation?

Back

To determine the coefficient, count the number of atoms of each element on both sides of the equation and adjust the coefficients to make them equal.

Front

What is the first step in balancing a chemical equation?

Back

The first step is to write down the unbalanced equation and count the number of atoms of each element on both sides.

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule; they cannot be changed when balancing equations.

Front

How do you balance the equation N2 + O2 → NO?

Back

Place a coefficient of 2 in front of NO to balance the equation: N2 + O2 → 2NO.

Front

Which of the following equations is balanced: PbO2 + 2H2 → ?, SO2 + H2O → H2SO4, 2Na + 2H2O → 2NaOH + H2?

Back

2Na + 2H2O → 2NaOH + H2 is balanced.

Front

How many HCl molecules are needed to balance Mg + __HCl → MgCl2 + H2?

Back

You need 2 HCl molecules to balance the equation.

Front

What coefficient should be placed in front of HNO3 in the equation Mn + __HNO3 → Mn(NO3)2 + H2?

Back

A coefficient of 2 should be placed in front of HNO3.