2.1.3 - Amount of Substance

• What is the unit used for the amount of substance?

  Moles
• How is the amount of substance calculated using mass?

  Using the formula $n =$$m/M$
• What is the formula for calculating the amount of substance from gas volumes?

  $n =$$PV/(RT)$
• How can the amount of substance be calculated from solution volume and concentration?

  Using the formula $n =$$CV$
• What does the term "anhydrous" refer to?

  A compound containing no water
• What is atom economy a measure of?

  The amount of starting materials as useful products
• Why is a high atom economy considered more sustainable?

  It produces less waste
• What is the formula for percentage atom economy?

  $\text{Percentage atom economy} =$$\frac{\text{Molecular mass of desired product} \times 100}{\text{Sum of molecular masses of all reactants}}$
• What is the Avogadro Constant (N₂)?

  6.02 x 10²³ mol⁻¹
• What does composition by mass refer to?

  The relative mass of each element in a compound
• What is an empirical formula?

  The simplest whole number ratio of atoms
• What does "hydrated" mean in chemistry?

  A compound that contains water
• What is an ideal gas?

  A gas with negligible space and no interactions
• What is the ideal gas equation?

  PV = nRT
• What is molar gas volume?

  Volume of 1 mole of gas
• What are the units for molar gas volume?

  dm³ mol⁻¹
• What is molar mass?

  Mass per mole of a substance
• What are the units for molar mass?

  g mol⁻¹
• What is a mole (mol)?

  Amount of substance with 12g of carbon-12 atoms
• How is the mole defined?

  By the number of particles in 12g of carbon-12
• What is a molecular formula?

  Number and type of atoms in a molecule
• What does percentage yield represent?

  Actual yield compared to theoretical yield
• What is the formula for percentage yield?

  Percentage yield = (Actual yield / Theoretical yield) x 100
• What is relative molecular mass?

  Average mass of one molecule compared to carbon-12
• How is relative molecular mass calculated?

  Compared to 1/12th the mass of carbon-12
• What does stoichiometry refer to?

  Relative quantities of substances in a reaction
• What is water of crystallisation?

  Water molecules in a crystalline structure
• Why is water of crystallisation important?

  It forms part of a compound's structure