C3.1 Chemical Formulae and Balancing Equations

C3.1 Chemical Formulae and Balancing Equations

Keywords

Atoms

Molecules

Elements

Compounds

Formula

Symbol equations

Law of Conservation of Mass

Multiple Choice

How many atoms are in this molecule?

You can click on the image to make it bigger.

• 1

• 2

• 3

• 4

Multiple Choice

How many hydrogen atoms are in this molecule?

You can click on the image to make it bigger.

• 1

• 2

• 3

• 4

Multiple Choice

What does the 'O' stand for in this molecule?

• hydrogen

• oxygen

• osmium

• carbon

Multiple Choice

How many oxygen atoms are in this molecule?

You can click on the image to make it bigger.

• 1

• 2

• 3

• 4

Fill in the Blank

Write the formula for this molecule.

Remember when written on paper the numbers need to be small and low against the letters!

Multiple Choice

How many oxygen atoms are in this molecule?

You can click on the image to make it bigger.

• 1

• 2

• 3

• 4

Fill in the Blank

Write the formula for this molecule.

Remember when written on paper the numbers need to be small and low against the letters!

Multiple Choice

This is aluminium oxide. How many atoms of oxygen are in this compound?

• 1

• 2

• 3

• 4

Fill in the Blank

Write the formula for this compound.

Fill in the Blank

This compound is called ammonia. Write the formula for ammonia.

Multiple Choice

This is a molecule of aluminium chloride. Select the correct formula.

• AlCl3

• Al2Cl3

• Al2Cl2

• ALCL3

Have a think. The answer is on the next slide.

Did you get it right? Remember to ask in the chat if you have a question!

The first row of blocks shows the formulae. The second row show the atoms in the formula.

This is a LAW in science. There is so much evidence for this, it is a TRUTH of the universe!

You will write your answers on the next slide.

Fill in the Blank

What do you think the mass of the products will be?

Remember the law of conservation of mass!

At the moment this is NOT balanced. There are different number of atoms on each side.

Multiple Choice

Calcium hydroxide is an alkali. It has the formula Ca(OH)₂

How many calcium atoms are in this formula?

• 1

• 2

• 3

• 4

Multiple Choice

Calcium hydroxide is an alkali. It has the formula Ca(OH)₂

How many oxygen atoms are in this formula?

• 1

• 2

• 3

• 4

Multiple Choice

Copper Nitrate is a salt. It has the formula Cu(NO₃)₂

How many oxygen atoms are in this formula?

• 2

• 3

• 5

• 6

Multiple Choice

Copper Nitrate is a salt. It has the formula Cu(NO₃)₂

How many nitrogen (N) atoms are in this formula?

• 2

• 3

• 5

• 6

Let's go through some examples and quick questions.

Answer on the next slide: How many hydrogen atoms are on the left (reactants)?

Multiple Choice

How many hydrogen atoms are on the left (reactants)?

• 1

• 2

• 3

• 4

Answer on the next slide: How many iron atoms are on the right (products)?

Multiple Choice

How many iron atoms are on the right (products)?

• 1

• 2

• 3

• 4

Answer on the next slide: How many carbon atoms are on the left (reactants)?

Multiple Choice

How many carbon atoms are on the left (reactants)?

• 1

• 2

• 3

• 4

Answer on the next slide: How many hydrogen atoms are on the right (products)?

Multiple Choice

How many hydrogen atoms are on the right (products)?

• 4

• 6

• 12

• 18

Answer on the next slide.

Multiple Choice

What is the mass of water (products) produced?

• 10 g

• 15 g

• 20 g

• 25 g

Multiple Choice

What is the mass of oxygen needed to react to make 50 g of water?

• 20 g

• 30 g

• 40 g

• 50 g

Multiple Choice

What is the mass of carbon was needed to react to form 900 tonnes of carbon dioxide?

• 300 tonnes

• 400 tonnes

• 500 tonnes

• 600 tonnes