Moles & Mass
This lesson covers:
- What the term 'mole' means
- What 'Avogadro's constant' is, and how to use it
What is the formula that links mass, moles, and Mr?
mass = moles x Mr
moles = mass x Mr
mass = moles2
|
Remember that when you use the formula:
It doesn't matter that it says Mr rather than Ar.
If you only have a single element, just use the Ar of that element.
What is the mass of 1 mole of sodium (Na)?
11 g
23 g
34 g
|
What is the mass of 0.25 moles of carbon dioxide (CO2)?
(Ar of C is 12, Ar of O is 16)
g
|
How many moles are there in 72g of water (H2O)?
(Ar of H is 1, Ar of O is 16)
moles
|
How many moles are there in 10.2g of ammonia (NH3)? Give your answer as a decimal.
(Ar of N is 14, Ar of H is 1)
moles
|
0.040 moles of an unknown compound is found to have a mass of 3.28 g.
Find the relative formula mass of the compound.
|
1.4 moles of an unknown compound is found to have a mass of 39.2 g.
Find the relative formula mass of the compound.
|
What is the mass of 4 moles of nitrogen gas (N2)?
(Ar of N is 14)
g
|