mole concept

• A mole is the amount of substance that contains 6.02 x 10^23 particles of that substance.
• A mole is the amount of substance in grams that contains the same number of particles as there are in 12 grams of carbon-12.
• Avogadro’s Law states that equal volumes of all gases under the same conditions at room temperature and pressure contain the same number of molecules.
• The average mass of one molecule of an element or compound compared to 112 the mass of an atom of carbon-12 is known as the atomic mass.
• Carbon is the standard 112 which is the atomic mass unit.
• Molar mass is the mass of 1 mole of a substance.
• Unit: g/mol or gmol-1.
• Relative Molecular Mass is the ratio of the mass of a compound compared to 112 mass of a carbon 12 atom.
• Molecular → Covalent compounds use Formula mass → Ionic compounds use Molar mass.
• Molar mass has a unit of grams per mole but relative molar mass has no unit, however, they are numerically equal.
• To calculate the relative molar mass and the relative formula mass you are adding the atomic masses of the elements in the compound.
• 1 mol of gas occupied 24dm3 at r.t.p = 24,000cm3.
• 1 mol of gas occupied 22.4dm3 at s.t.p = 22,400cm3.
• Concentration is the amount of solute dissolved in a given volume of solution.
• Concentration can be expressed in terms of: Mass Concentration → mass of solute dissolved in 1dm3 or 1000 cm3 of solution.
• Unit - g/dm3 or gdm-1.
• Molar Concentration →moles of a solute dissolved in 1dm3 or 1000 cm3 of solution.
• Unit - mol/dm3 or moldm-1.
• Mole Fraction → 5 mol/dm3 = 5 moles are in 1dm3.