A lot of people have trouble with balancing equations, so I’m going to explain how I teach them in the hope it might help a few people. I don’t know if it’ll work for you, but I teach my pupils how to balance them using Lego. Let’s use a displacement reaction as an example:
Obviously, you can’t change any of the formulae, so I’ve boxed them off as a reminder. You can only put numbers in front of the different elements or compounds in the equation to balance it. To start with allocate a different coloured lego to each element in the equation. I’m going to use blue for aluminium, green for copper, yellow for sulfur and red for oxygen. I’m also going to use circles because I’m too lazy to draw lego. Just, I don’t know, pretend they’re Lego:
Now, that’s already looking a little more complicated. But remember, all we want to do is ensure we’ve got the same number of each element (each colour circle) on either side of the dotted line. You can see at the moment we’re short of one aluminium (blue), two sulfurs (yellow), and quite a few oxygens (red)! Since aluminium’s the easiest one to solve, let’s do that first - you just need one more blue circle on the left, so if we put a two in front of Al, that solves it:
We also need another two sulfurs. We can achieve that by putting a 3 in front of CuSO4. However, we’ve got to bear in mind that doing this multiplies all the elements in that compound by three. So, as well as ending up with three sulfurs, we’ll also get three coppers and twelve oxygens:
That turns out to have been quite useful, since we’ve now got the right number of sulfurs and oxygens. However, we’ve now got three coppers on the left, when we only have one on the right. That’s easy to fix with a three in front of copper:
And there we have our balanced equation - you can see we’ve now got the exact right number of each element (or each coloured circle/lego). Hope that method helps you!