Moles Flashcards
Where can you find Relative Formula Mass of an atom?
The upper number in the periodic table.
What is the sign for Relative Formula Mass of one atom?
Ar
What is the sign for Relative Formula Mass of a compound?
Mr
How do you calculate Mr (Relative Atomic Mass) of a compound?
- Find the relative atomic mass of each element in the compound.
Write out the chemical equation for the compound.
Work out how many of each atoms.
Total weight of each atom.
Total weight of all atoms.
How many particles are in a mole?
6.02 x 1023
What is the Avogadro number?
6.02 x 1023
I mole of sodium contains what?
6.02 x 1023 atoms of sodium.
This is equivalent to the relative atomic mass of sodium in the periodic table and can be expressed in grams.
1 mol of sodium has a mass of 23g.
A mole is a measure of an amount of substance.
State the mols/mass/Mr triangle:
Mass
___________
Moles x Mr
What is the molar volume of a gas?
24dm3 or 24000cm3
e.g. 3 moles of hydrogen = 3 x 24 = 72dm3
How do you calculate the mass of a particular element in a compound?
% of element =
Ar x number of atoms
____________________ x 100
Mr of the compound
In any chemical reaction mass is always conserved. how can be express this:
Total Mr of the reactants equals total Mr of the products.
What is the notation for moles?
n
What is the notation for mass g
m g
(the unit is g)
What is the notation for Mr or molar mass?
Mm g mol -1
