MOLES

• mole - is a standard scientific unit for measuring the amount of any substance, such as atoms, molecules, or ions
• The molar mass of an atom of an element is its atomic mass in grams.
• molar mass of an element or compound - is the sum of the atomic masses of all its atoms
• The atomic mass in grams contains 6.022 x 10^23 atoms (Avogadro’s

  number) of the element.
• number of moles = number of molecules / (6.022 x 10^23 molecules/mole)
• 1 mole = 6.022 x 10^23 ions
• Stoichiometry - The area of chemistry that deals with the quantitative relationships between reactants and products.
• Mole Ratio - a ratio between the moles of any two substances involved in a chemical reaction
• The coefficients used in mole ratio expressions are derived from the coefficients used in the balanced equation.
• The mole ratio is used to convert the number of moles of one substance to the corresponding number of moles of another substance in a stoichiometry problem.
• The mole ratio is used in the solution of every type of stoichiometry problem.
• Convert the quantity of starting substance to moles (if it is not already in moles)

  Mole Ratio Method Step 1
• Convert the moles of starting substance to moles of desired substance.

  Mole Ratio Method Step 2
• Convert the moles of desired substance to the units specified in the problem.

  Mole Ratio Method Step 3
• moles = grams (1 mole / molar mass)
• grams = moles (molar mass / 1 mol)
• atoms = moles (6.022 x 10^23 atoms / 1 mol)
• molecules = moles (6.022 x 10^23 molecules / 1 mol)