Balancing Chemical Equations

Balancing Equations

Identify the REACTANTS & PRODUCTS

(You may want to write a word equation )

Balancing Equations

Using correct formulas and symbols, write an unbalanced

equation for the reaction.

{A SKELETON EQUATION}

Balancing Equations

Balance atoms ONE element at a time by inserting coefficients.

START with elements that appear in only one reactant and

one product, and balance the atoms of those elements first.

Balancing Equations

IF a polyatomic ion appears on both sides of the equation,

treat it as a single unit.

Balancing Equations

Leave Oxygen and Hydrogen for the last elements to

balance.Double-check to be sure that the number of atoms of each element is the same on both

sides of the equation

Balancing EquationsPRACTICE PROBLEMS

1. When propane (C3H8) burns completely in air(O2), the reaction forms carbon dioxide and water vapor. Write and balance the equation for this reaction.

 

When propane (C3H8) burns completely in air(O2), the reaction forms carbon

dioxide and water vapor.. 

Step 1 the Skeleton Equation Step 1 the Skeleton Equation

C3H8 +O2 CO2 + H2O

Step 2 Count and Compare elementsStep 2 Count and Compare elements

(3 – C) 3(1 – C)

(8 – H) 4(2 –H)

(2 – O) x 5 (3 – O)

C3H8 + 55 O2 33 CO2 + 44 H2O

Step 3 Use Coeffeicients to BalanceStep 3 Use Coeffeicients to Balance

Balance the following skeleton chemical equations:

a. KI(aq) + Cl2(g) → KCl(aq) + I2(s)

b. Al(s) + H2SO4(aq) → Al2(SO4)3(aq) + H2(g)

c. Online problem check

Balancing EquationsPRACTICE PROBLEMS online