1. BALANCING EQUATIONS NO3 - Balancing equations made easy

2. Here is an equation that needs to be balanced: Fe + CO 2 Fe 2 O 3 + CO Step 1: list all the elements neatly under the arrow Fe O C

3. Fe + CO 2 Fe 2 O 3 + CO Fe O C Now count up how many you have on each side

4. Count up how many you have on each side Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 First the Fe

5. Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 3 + 1 = 4 2 Help – there are 3 + 1 on the left 3 in Fe 2 O 3 Plus 1 in CO We could write it as C 1 O 1 – but we don’t put the 1 Now the O

6. Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 4 2 11 Now the C

7. Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 4 2 11 We need 1 more Fe on the RIGHT And 2 more O on the right But the C are balanced – 1 each side. We need to change the number of O and then rebalance the C This is what we have

8. Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 4 2 11 Tip: Because we have Fe on its own on the right, we can easily balance that at the end. So, lets look at balancing the O, then C

9. Fe + CO 2 Fe 2 O 3 + CO Fe O C 21 4 2 11 So, lets look at balancing the O To balance the O we need 2 more on the RIGHT To do that we need to have 2 CO 2

10. Fe + 2 CO 2 Fe 2 O 3 + CO Fe O C 21 4 1 So, lets look at balancing the O Now let’s count up the C and O on the right again

11. Fe + 2 CO 2 Fe 2 O 3 + CO Fe O C 21 4 1 So, lets look at balancing the O 2 x 2 = 4 2 x 1 = 2

12. Fe + 2 CO 2 Fe 2 O 3 + CO Fe O C 21 4 1 4 2 The O is now balanced – great! But now the C is not!! Sigh! So, we now balance the C

13. Fe + 2 CO 2 Fe 2 O 3 + 2 CO Fe O C 21 4 2 The only way to add more C on the left is to add more CO

14. Fe + 2 CO 2 Fe 2 O 3 + 2 CO Fe O C 21 4 2 The only way to add more C on the left is to add more CO So let’s now count up the C and O on the LEFT

15. Fe + 2 CO 2 Fe 2 O 3 + 2 CO Fe O C 21 4 2 The only way to add more C on the left is to add more CO 3 + 2 = 5 Hmm. That is not going to work. On the RIGHT we have CO 2 – so as we add more CO 2 on the right, O can only go up in 2, 4, 6 etc We need an EVEN number of O on the LEFT so we can balance them

16. Fe + 2 CO 2 Fe 2 O 3 + 2 CO Fe O C 21 4 2 3 + 2 = 5 We need an EVEN number of O on the LEFT so can balance them Let’s try 3 CO on the left. See what happens

17. Fe + 2 CO 2 Fe 2 O 3 + 3 CO Fe O C 21 4 2 3 + 3 = 6 Let’s try 3 CO on the left. See what happens OK, we now have six O on the left – we can get six O on the right too So we can balance the O Let’s see how many C we have now

18. Fe + 2 CO 2 Fe 2 O 3 + 3 CO Fe O C 21 4 2 6 Let’s balance the C First count up the C on the left again 3 So we need one more C on the right to make it 3 - 3 Don’t worry about the O. We will get back to that

19. Fe + 3 CO 2 Fe 2 O 3 + 3 CO Fe O C 21 3 6 3 We need one more C on the right to make it 3 - 3 We do that by having 3 CO 2 on the right Now C is balanced, we need to balance O

20. Fe + 3 CO 2 Fe 2 O 3 + 3 CO Fe O C 21 3 6 3 Now C is balanced, we need to balance O Count up the O on the right 3 x 2 = 6 Now O and C are balanced We just need to balance Fe And that is easy

21. 2 Fe + 3 CO 2 Fe 2 O 3 + 3 CO Fe O C 22 3 6 3 6 The equation is balanced