Chemical Equation

## Chemical changes are shown using chemical equations

One way to show a chemical reaction is to write a word equation.

It’s not as quick as using chemical symbols and you can’t tell straight away what’s happened to each of the atoms, but it’s dead easy.

Here’s an example-you’re told that methane burns in oxygen giving carbon dioxide and water

Methane + Oxygen - Carbon Dioxide + Water

The molecules on the left-hand side of the equation are called reactants(because they react with each other)

The molecules on the right-hand side are called the products(because they’ve been produced from the reactants

## Symbol equations show the atoms on both sides

Chemical changes can be shown in a kind of shorthand using symbol equations.

Symbol equations just show the symbols or formulas of the reactants and products

Magnesium + Oxygen - Magnesium Oxide

2Mg + 02 - 2Mg0

## Symbol equations need to be balanced

There must always be the same number of atoms on both sides-they can’t just disappear

You balance the equation by putting numbers in front of the formulas where needed.

Take this equation for reacting sulfuric acid with sodium hydroxide:

H2S04 + Na0H - Na2S04 + H20

The formulas are all correct but the numbers of some atoms don’t match up on both sides

You can’t change formulas like H2SO4 to H2SO5. You can only put numbers in front of them.

The more you practise, the quicker you get, but all you do is this:

Find an element that doesn’t balance and pencil in a number to try and sort it out

See where it gets you. It may create another imbalance, but if so, pencil in another number and see where that gets you

Carry on chasing unbalanced elements and it’ll sort itself out pretty quickly

# Chemical Equation

## Chemical changes are shown using chemical equations

One way to show a chemical reaction is to write a word equation.

It’s not as quick as using chemical symbols and you can’t tell straight away what’s happened to each of the atoms, but it’s dead easy.

Here’s an example-you’re told that methane burns in oxygen giving carbon dioxide and water

Methane + Oxygen - Carbon Dioxide + Water

The molecules on the left-hand side of the equation are called reactants(because they react with each other)

The molecules on the right-hand side are called the products(because they’ve been produced from the reactants

## Symbol equations show the atoms on both sides

Chemical changes can be shown in a kind of shorthand using symbol equations.

Symbol equations just show the symbols or formulas of the reactants and products

Magnesium + Oxygen - Magnesium Oxide

2Mg + 02 - 2Mg0

## Symbol equations need to be balanced

There must always be the same number of atoms on both sides-they can’t just disappear

You balance the equation by putting numbers in front of the formulas where needed.

Take this equation for reacting sulfuric acid with sodium hydroxide:

H2S04 + Na0H - Na2S04 + H20

The formulas are all correct but the numbers of some atoms don’t match up on both sides

You can’t change formulas like H2SO4 to H2SO5. You can only put numbers in front of them.

The more you practise, the quicker you get, but all you do is this:

Find an element that doesn’t balance and pencil in a number to try and sort it out

See where it gets you. It may create another imbalance, but if so, pencil in another number and see where that gets you

Carry on chasing unbalanced elements and it’ll sort itself out pretty quickly