Unit 2 Summary
Key Terms - you should know the definitions of the following terms and be able to use them correctly when discussing chemistry.
___  isotopic abundance
___  atomic mass unit (u)
___  atomic mass
___  molecular mass
___  formula unit mass
___  macroscopic
___  Avogadro's constant NA
___  molar mass
___  molecular element
___  compound
___  law of constant composition
___  mass spectrometer
___  combustion analyser
___  percentage composition
___  empirical formula
___  molecular formula
___  quantitative analysis
___  concentration
___  molar concentration
___  parts per million
___  dilution
___  mole ratio
___  stoichiometry
___  excess reagent
___  limiting reagent
___  yield
___  actual yield
___  theoretical yield
___  percentage yield



Problems that you should be able to solve
• Use mass and molar mass to calculate the number of entities.
Use the periodic table to calculate atomic mass and molecular mass.
Use mass, amount in moles, molar mass, and number of entities to calculate an unknown value.
Calculate the empirical formula of a compound.
Calculate the molecular formula of a compound.
Calculate the percentage composition by mass of a compound.
Use the percentage concentration formula to calculate %V/V and %W/V of a solution.
Use the molar concentration formula to solve for the unknown value.
Use the dilution concentration formula to solve for the unknown value.
Use a balanced chemical equation to calculate the masses of the reactants.
Use a balanced chemical equation to calculate the numbers of entities and the masses of the reactants and products.
Use a balanced equation to determine the limiting reagent in a reaction and calculate the mass of a product formed.
Use actual yield and theoretical yield to calculate percentage yield.