— a mole of a substance is the amount that contains the same number of units as a Carbon-12 atom
— A Carbon-12 atom contains 6.02 • 10^23 units = Avogadro Constant
— 1 mole of anything = 6.02 • 10^23 units of it
— 1 unit of an substance might weigh differently from 1 unit of another
e.g. 1 unit of Sodium > 1 unit of Carbon
→ 1 mole of Sodium (23g) > 1 mole of Carbon (12g)
— the mass of a mole is the Mr value of the substance, in grams
e.g. Mr of Magnesium (Mg) = 24
1 mole of Mg = 24***g***
Mr of Oxygen (O2) = 32 !!*not* 16 because Oxygen exists in molecules (O2)!!
1 mole of O2 = 32***g***
— coefficient of a compound → the number of moles of that compound
— moles measure the amount of chemical
<aside> 📌 number of moles = current mass of the substance / the mass of 1 mole of that substance [g/mol]
</aside>
— the total mass of the reactants = the total mass of the products
— Avogadro's Law → the volume of 1 mole of any gas at rtp. (room temperature and pressure) is always 24dm3
e.g. 1 mole of CO2 = 24dm3
e.g. 1 mole of O2 = 24dm3
1dm3 = 1000cm3
<aside> 📌 number of moles of a gas = current volume of the gas / 24dm3 [dm3/24dm3]
</aside>
— concentration → amount of solute dissolved in 1dm3 of a solution
units: