Mole Calculations

How many moles of water in a 250ml glass?

Clue: 1ml=1g

• 13.4

• 13.8

• 14.0

• 15.2

How many moles of carbon in a 100g lump of coal?

• 8.3

• 8.4

• 8.5

• 8.6

How many moles of magnesium in a 20g strip?

• 0.81

• 0.82

• 0.83

• 0.84

How many moles of helium in a 15g balloon?

The balloon alone weighs 14g.

• 0.1

• 0.2

• 0.25

• 0.025

Moles = massxMr

• True

• False

Moles = mass/Mr

• True

• False

Define empirical formula

• Actual number of atoms of an element in a molecule

• Simplest ratio of atoms of an element in the molecule

• Average mass of an atom of an element

1 mole of carbon dioxide has a mass of 44g. what is the mass of 1 molecule? (Avogadro's number = 6x10²³⁾

• 2.64x10²⁵

• 7.33x10^-23

What is the mass of one mole of sulphur?

• 10

• 12

• 32

• 44

0.5 moles of an unknown substance has a mass of 22g. Calculate the Mr.

• 11

• 44

• 32

• 66