Topic 5: Formulae, Equations and Amounts of Substance

Question 1

What is a mole?

Answer 1

• the mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon-12
• 6.02 x 10^23
• a number that is used so that reactions can be displayed in a smaller number since there are so many atoms and molecules

Question 2

What is Avogadro’s Constant?

Answer 2

• number of particles (atoms, molecules or units) in 1 mole

- 1 mole has 6.02 x 10^23

Question 3

What is molar mass?

Answer 3

• the molar mass is the mass of one mole of substance in grams
• molar mass of an atom is known as the relative atomic mass (Ar)