Flashcards in Moles Calculations Deck (11):
What is the mass number?
Total number of protons and neutrons in an atom
What are isotopes?
Atoms of the same element that have the same number of protons but different numbers of neutrons
What is the relative atomic mass?
The average mass of isotopes of an element compared to the mass of a Carbon-12 atom
How to work out RAM
²⁴Mg = 77.6%
²⁵Mg = 10.1%
²⁶Mg = 11.3%
(24 x 78.6) + (25 x 10.1) + (26 x 11.3) / 100
How do you calculate relative formula mass?
NH₃ = N + (Hx3) = 14 + 3 = 17
How to calculate percentage abundance
total mass of element in compound / RFM of compound x 100
How to calculate mole calculations using relative atomic mass and relative formula mass
mass = number of moles x RFM
If the molecular formula is H₂O₂, what is the empirical formula?
How to work out the empirical formula from the mass of each element in a compound
• Determine the mass or percentage of elements.
• Divide the given mass or percentage by their RAM.
• Calculate the ratio of the atoms by dividing by smallest value.
1 : 2
How to work out volume with moles
• volume = moles x 24(dm³)
• volume = moles x 24000(cm³)