Chemistry - Topic 4 Chemical Calculations

Question 1

Relative Formula Mass

Answer 1

The mass of a molecule or formula unit of a substance relative to the mass of a carbon-12 atom

Question 2

What is a mole?

Answer 2

The unit for the amount of a substance

Question 3

What is 1 mole = to?

Answer 3

1 mole = 6.02 x 10^23 particles

Question 4

What is one mole of carbon?

Answer 4

The mass of 1 mole of carbon is 12 g

Question 5

Finding the number of moles in a given mass


Answer 5

Mass in g / Relative Formula Mass = Number of moles

Question 6

Molecular formula


Answer 6

The actual number of atoms of each element in a molecule

Question 7

Concentration is…

Answer 7

The amount of substance per unit volume

Question 8

Concentration is usually measured in..

Answer 8

Concentration is usually measured in moles per cubic decimeter (mol/dm^3)

Question 9

Molecular formula

Answer 9

Tells you the number of atoms of each element in a single molecule

Question 10

What is Avogadro’s law?

Answer 10

Avogadro’s law states that one mole of any gas occupies 24 dm³ at room temperature and pressure

Question 11

Using Avogadro’s law to calculate moles from volume


Answer 11

Moles = Volume / 24

Question 12

Converting moles to concentration

Answer 12

• Divide moles by volume to get concentration

Question 13

Converting concentration from mol/dm³ to g/dm³

Answer 13

Multiply concentration in mol/dm³ by molar mass to get concentration in g/dm³