Balancing Chemical Equations

Balancing Chemical Equations Just follow these steps……. It’s quite easy really

Then all you do is list the atoms that are involved on each side of the arrow Mg + O2 MgO Firstly you need an equation with the correct “formulae” in………. You’ll probably be given this in the question Just like this one Mg + O2 MgO Mg O

Mg + O2 MgO Mg + O2 MgO Mg O Mg O 1 1 2 1 Then start balancing: [1] Just count up the atoms on each side 1 1 2 1 [2] The numbers aren’t balanced so then add “BIG” numbers to make up for any shortages 2 2 2 And adjust totals

2 2 1 Mg + O2 MgO 2 2 Mg O But the numbers still aren’t equal, so add another “BIG” number 2 2 And adjust totals again NOW BOTH SIDES HAVE EQUAL NUMBERS OF ATOMS WE SAY THAT THE EQUATION IS BALANCED!!

Try to balance these equations using the same method: [1] Na + Cl2 NaCl [2] CH4 + O2 CO2 + H2O [3] Li + HNO3  LiNO3 + H2 [4] Al + O2 Al2O3

How did you get on?? Here are the answers: [1] 2 Na + Cl22 NaCl [2] CH4 + 2 O2 CO2 + 2 H2O [3] 2 Li + 2 HNO3 2 LiNO3 + H2 [4] 4 Al + 3 O22 Al2O3 HOPE YOU’VE GOT THE IDEA… REMEMBER TO CHECK THAT YOU CAN DO ELECTROLYSIS EQUATIONS TOO

Electrolysis equations ones to check [a] Cu2+ + e- Cu [b] Cl- - e- Cl2 [c] H+ + e- H2 [d] Br - Br2 + e-

The answers are…. Remember to balance the charges on each side of the arrow [a] Cu2+ + 2 e-Cu [b] 2 Cl- - 2 e- Cl2 [c] 2 H+ + 2 e-H2 [d] 2 Br -Br2 +2 e-

Hope that makes things a bit clearer…. Just remember it’s all about balance

Balancing Chemical Equations