Balanced chemical equation for Magnesium oxide

If you think balancing chemical equations is too difficult, then this videojug film is for all your unbalanced equations. This video will show you how to balance chemical equations whether simple or complex.

Hi, I'm Donald Sinclair. I'm a science teacher at Greater London Tutors, and today, we're going to be looking at a few topics in Chemistry. This is how to balance chemical equations.

Balancing equations is a very important skill in Chemistry; take this example, the reaction of Magnesium with Oxygen. Magnesium reacts with oxygen in the air to form Magnesium Oxide. If you look at what is happening with the atoms, a Magnesium atom reacts with an Oxygen molecule to give a Magnesium Oxide molecule.

Problem here is that one of the atoms of Oxygen has gone missing. This can't happen in chemical equations, atoms cannot be created or destroyed, they can only change partners to form new bonds or break old ones. You think of the example of a set of scales, the scales have to balance what was before the reaction, the reagents and what's after the reaction, the products.

So what we do is that we balance; we put in two Magnesium atoms and two Magnesium Oxide molecules. This means that we have the same, before and after the reaction, so the equation is balanced. Let's look at a more complicated example.

Sodium reacts with Water to form Sodium Hydroxide and Hydrogen gas. If you're doing an equation where you have pretty simple molecules which are only composed of one element, then you can often leave them to lots, to help take up any change to balance the equation. Here for example, we know we're going to need two Hydrogens for the Water, now we have three on this side, if you have three Hydrogens that don't balance very easily.

So we think about what numbers we can put in to make it balance. Here now, we have four Hydrogens, so if we put two in front of the water now, we have four Hydrogens there as well. However, we also have two Sodiums now.

If we put two in front of the Sodium, that balances the equation. It's often a method of trial and error to find the appropriate numbers to go in front of the appropriate molecules but with enough practice, it becomes second nature and you should never find an example where balancing it becomes too difficult. And that's how you balance equations. .