Balancing Chemical Equations Page 233

Components of chemical equations Starting materials – reactants Conditions of reactants – state Proportions of reactants – coefficients Instructions for reacting – ‘+’ sign Resulting product – products Proportions of products - coefficients

The Balancing Act Step 1: Write the word equation Magnesium + oxygen magnesium oxide Step 2: Write the skeleton equation Mg(s) + O2(g) MgO(s) Step 3: Count the # and kinds of atoms Mg(s) + O2(g) MgO(s) 1 Mg atoms 1 Mg atom 2 O atoms 1 O atom

The Balancing Act Step 4: Write coefficients to balance 2Mg(s) + O2(g) 2MgO(s) 2 Mg atoms 2 Mg atoms 2 O atoms 2 O atoms

The Balancing Act Step 1: methane + oxygen carbon dioxide + water Step 2: CH4(g) + O2(g) CO2(g) + H2O(l) Step 3: 1 C atom 1 C atom 4 H atoms 2 H atoms 2 O atoms 3 O atoms Step 4: CH4(g) + 2O2(g) CO2(g) + 2H2O(l)

The Balancing Act Step 1: zinc (s) + silver nitrate (aq) zinc nitrate (aq) + silver (s) Step 2: Zn (s) + AgNO3 (aq) Zn(NO3)2 + Ag (s) Step 3: 1 Zn 1 Zn atom 1 Ag 1 Ag atom 1 NO3 2 NO3 Zn(s) + 2AgNO3 (aq) Zn(NO3)2 (aq) + 2Ag (s)

Try This: Write a balanced equation for the reaction between iron (III) nitrate and sodium hydroxide to produce iron (III) hydroxide and sodium nitrate.

Skeleton equation: Fe(NO3)3 + NaOH Fe(OH)3 + NaNO3 1 Fe atom 1 Fe atom 3 NO3 ion 1 NO3 ion 1 Na atom 1 Na atom 1 OH ion 3 OH ions

Balanced Equation Fe(NO3)3 + 3NaOH Fe(OH)3 + 3NaNO3 1 Fe atom 1 Fe atom 3 NO3 ions 3 NO3 ions 3 Na atoms 3 Na atoms 3 OH ions 3 OH ions

Steps to balancing chemical equations - Balance the # of atoms simply by adding a coefficient in front of the chemical formula containing the element or compound you are trying to balance 1. Balance all other atoms except hydrogen and oxygen first 2. Balance oxygen 3. Balance hydrogen 4. Check – to ensure that all the atoms are now balanced

Rules to Remember: Do: write proper formulas in skeleton equations Do: double-check that balancing one element doesn't unbalance another Never Ever Not even once Change the subscripts!

(iodine) Zn (uranium) have the (boron)(lutetium)(einsteinium) (iodine) Zn (uranium) have the (boron)(lutetium)(einsteinium). These (tungsten)ill Cm! Page 236 # 3 – 8 worksheet