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1.2.2 Avogadro’s Constant & The Mole - Coggle Diagram
1.2.2 Avogadro’s Constant
& The Mole
the Avogadro constant
The number of particles per mole (6.02 × 10^23 mol^-1)
Mole
the amount of any substance containing as many elementary particles as there are carbon atoms in exactly 12g of the carbon-12 isotope
Molar Mass (Mr)
The molar mass of a substance is the mass, in grams, of one mole (g mol^-1)
relationship between moles, mass and molar mass
Moles = Mass/Molar mass
Mass= moles x molar mass
Molar mass= mass/moles
Calculations/Examples
2.00 x 18.02 = 3.60 x 10^1 g (3 sf)
Masses to moles: Calculate the number of moles of
560 g of ethene (C2H4) molecules
560/28.06 = 2.00 × 10^1 mol (3 sf)
Moles to mass: 2.00 moles of water
Significant figures
Zeros to the right of the decimal place are important.
zeros in a whole number with the decimal shown are significant.
zeros in front of the first non-zero number are not significant (e.g. 0.002)
rules for ‘zeros’ when manipulating significant figures:
Scientific Notations
Example: 47.7g = 4.77 x 10^1g
Example: 0.0067g = 6.7 x 10^-3g