How to work with Moles and Calculations

Avogadro’s constant is a massive number, and can be really difficult to comprehend when you are completing calculations with moles. Imagine this:

• If there were a mole of rice grains, all the land area in the whole world would be covered
with rice to a depth of about 75 metres.
• One mole of rice grains is more grains than all the grain that has been grown since the beginning of time.
• Computers can count at the rate of over 800 million counts per second. At this rate it would take a computer over 25 million years to count to Avogadro’s constant.
• A mole of marshmallows would cover the United States to a depth of 600 miles
• In order to put a mole of rain drops in a 30 metre (about 100 feet) diameter tank, the sides of the tank would have to be 280 times the distance from the Earth to the Sun.

If you are studying GCSE science you need to be able to complete calculations with moles, and masses. For help with this try our new revision guide “How to work with Moles and Calculations”. It explains how to calculate relative formula mass, how to use the moles/mass/formula mass equation, and how to calculate the number of atoms in compounds. Included are questions to try, and answers to check your understanding.

To see the guide click the picture below.