Quantitative chemistry

• A mass spectrometer is a way of weighing atoms.
• Atoms combine to form molecules or groups of ions.
• Prepare magnesium oxide by heating a magnesium ribbon in a crucible.
• One mole of each of these different substances contains the same number of atoms, molecules or formula units, this is called the Avogardo Constant.
• Number of moles = mass/molar mass
• One mole of any gas occupies 24dm3 at room temperature (r.t.p.)
• Number of moles = volume/molar volume
• Concentration = amount of solute/volume of solution
• Number of moles in a solution = (molar concentration/100) x volume of solution.