2 Minute Drill

HomeworkComplete the Chemical Equation worksheet

Learner ObjectiveLearner will be able to balance the reactants and products of a

chemical reaction equation.

Lec: Balancing Chemical Equations

NaOH + HCl NaCl + H2OWhen balancing a chemical equation the quantity and types of elements in the reactants has to be equal to the quantity and types of elements in the products.

NaOH + HCl NaCl + H2OStep 1. Break the reactants and products down into the type of elements.

Na NaO OH HCl Cl

NaOH + HCl NaCl + H2OStep 2. Place the quantity of each element in the reactants and products.

Na:1 Na:1O:1 O:1H:2 H:2Cl:1 Cl:1

NaOH + HCl NaCl + H2OStep 3. Determine if the quantities of each element are the same. If they are you will state “The chemical equation is balanced. If not, state which elements are not.

Na:1 Na:1O:1 O:1H:2 H:2Cl:1 Cl:1

Fe(s) + O2 Fe2O3

Step 1:

Fe FeO O

Fe(s) + O2 Fe2O3

Fe: 1 Fe: 2O: 2 O: 3

Is this chemical equation balanced?

The chemical equation is not balanced because both Fe and O are not equal.

HCl + O2 Cl2 + H2O

Is this chemical equation balanced?

Balancing a chemical equation with a Chemical Group

Pb(NO3)2 + KI PbI2+ KNO3

Balancing a chemical equation with a Chemical Group

Pb(NO3)2 + KI PbI2+ KNO3

NO3 is a chemical group on both sides of the chemical equations.

Balancing an chemical equation with a Chemical Group

Pb(NO3)2 + KI PbI2+ KNO3

Step 1Pb: Pb: NO3: NO3 :K: K :I: I:

Balancing an chemical equation with a Chemical Group

Pb(NO3)2 + KI PbI2+ KNO3

Pb: 1 Pb :1NO3: 2 NO3 :1K: 1 K :1 I: 1 I: 2

Is this chemical equation balanced?

Challenger Balancing a Chemical Equation when the number of elements on

both sides are not equal.

Fe(s) + O2 Fe2O3

Fe: 1 Fe: 2O: 2 O: 3

Fe(s) + 3O2 2Fe2O3

Step 3:(reactants) (products)Fe: 1 Fe: 2O: 2 x 3 = 6 O: 3 x 2 = 6

Fe(s) + 3O2 2Fe2O3Step 3:The increase in O on the product side causes the Fe to increase too and now needs to be increased.

Fe: 1 Fe 2 x 2 = 4O: 2 x 3 = 6 O: 3 x 2 = 6

4 Fe(s) + 3 O2 2 Fe2O3

Fe 1 x 4 = 4 Fe 2 x 2 = 4O 2 x 3 = 6 O 3 x 2 = 6

4 Fe(s) + 3 O2 2 Fe2O3

What does this chemical reaction make?

4 Fe(s) + 3 O2 2 Fe2O3

What does this chemical reaction make?

Answer: Rust!

Balancing an chemical equation with a Chemical Group

Pb(NO3)2 + KI PbI2+ KNO3

Pb: 1 Pb :1NO3: 2 NO3 :1K: 1 K :1 I: 1 I: 2

Pb(NO3)2 + KI PbI2+ 2KNO3

Pb: 1 Pb :1NO3: 2 NO3 :1 x 2 =2K: 1 K :1 I: 1 I: 2

Pb(NO3)2 + 2KI PbI2+ 2KNO3

Pb: 1 Pb :1NO3: 2 NO3 :1 x 2 = 2K: 1 x 2 = 2 K :1 x 2= 2 I: 1 I: 2

Pb(NO3)2 + 2KI PbI2+ 2KNO3

Pb: 1 Pb :1NO3: 2 NO3 :1 x 2 =2K: 1 x 2 = 2 K :1 x 2= 2 I: 1 x 2 = 2 I: 2

H2SO4 + NaOH HOH + Na2SO4