5: Amounts of substance Flashcards
Mol definition and equation
Mol = amount of a substance, in grams, that has the same number of particles as there are in 12g of carbon-12.
Mol = Mass(g)/Mr
Avogadro constant definition and equation
One mole of any species contains 6.02x10(23) particles of said species.
No. particles = moles x 6.02x10(23)
Empirical formula definition and basic equation
Simplest whole number ratio of each element in a compound
- Divide each mass by its Mr
- Divide all by the smallest value calculated
- Whole numbers will be the empirical formula
Molecular formula definition and basic equation
Exact number of atoms of each element present in a compound
Work out how many times the Mr of empirical formula fits into Mr of molecular formula and multiply
Ideal gas equation and symbol meanings
pV=nRT
p= pressure (Pa)
V= volume (m2)
n= mols
R= gas constant (8.314)
T= temperature (K)
How do you convert celsius to kelvin?
+273
cm3 -> dm3?
/1,000
cm3 -> m3?
/1,000,000
dm3 -> m3?
/1,000
Calculation for moles of gases, what does it assume?
Mol = Vol/24
Assumes 1 atmosphere of pressure and room (25) temperature
Calculation for concentration?
Concentration = moles/volume
What colour is methyl orange in acidic solution?
red
What colour is methyl orange in basic solution?
yellow
What colour is phenolphthalein in acidic solution?
colourless
What colour is phenolphthalein in alkaline/basic solution?
pink
