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 Equations
PRACTICE 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
C3H8 +O2  CO2 + H2O
Step 2 Count and Compare elements
(3 – C)
3(1 – C)
(8 – H)
4(2 –H)
(2 – O) x 5
(3 – O)
Step 3 Use Coeffeicients to Balance
C3H8 + 5 O2  3 CO2 + 4 H2O
Balancing Equations
PRACTICE PROBLEMS
online
Balance the following skeleton chemical equations:
a. KI(aq) + Cl2(g) → KCl(aq) + I2(s)
b. Al(s) +
H2SO4(aq) →
Al2(SO4)3(aq) +
c. Online problem check
H2(g)