Quantative Chemisrty Flashcards
What is the ram of an atom compared to
The carbon 12 isotope
How do you calculate the % of an element in a compound
Total RAM of element ➗ RFM x 100
What is RAM
It’s the mass of the atom compared to the carbon 12 isotope which has a mass of exactly 12 and it is the weighted mean mass of the mass numbers
What is RFM
The sum of the relative atomic mass of all the atoms present in the formula of a substance
What is the mass mole and RFM triangle
M.
N. RFM
(Mol)
What is the emperical formula?
It’s the simplest whole number ratio of the atoms of each element in a compound.
What is the molecular formula
It is the actual number of atoms of each element in a molecule
How do you work out molecular formula
- Work out RFM of empirical formula
- Divide the given RFM mass by the calculated RFM using empirical formula in step 1
- Multiply each subscript by the whole number resulted in step 2
How do you find the percentage yield?
Actual yield ➗ theoretical yield x 100
Reasons for yield not being 100%
Side reaction
Reactants may not be 100% pure to being with
May be impossible to separate the product fully out of the reaction mixture.
Reactions are reversible
Define hydrated
Solid crystals contain water of crystallisation
Define anhydrous
Does not contain water of crystallisation
Define water of crystallisation
Water that is chemically bonded into the crystal structure
Define degree of hydration
The number of moles of water of crystallisation chemically bonded in 1 mole of the compound
Define dehydration
Removal of water of crystallisation
