Introduction to Stoichiomentry

Introduction to Stoiciomentry

• The word stoichiomentry derives from the Greek words: stoicheion (meaning "element") and metron (meaning "to measure").  Stoichiometry deals with calculations about the masses, volumes, or number of particles of reactants and products involved in a chemical reaction

 

• Prior Knowledge
  • In order to do stoiciomentric calculations you MUST be albe to clacluate molar mass.
  • Recall that molar mass is the SUM of the atomic masses from the periodic table.
  • Example:  Ca(NO3)2  molar mass is calculated as follows:
    • 1 calcium x (40.08 g atomic mass) = 40.08 g
    • 2 nitrogen x (14.01 g atomic mass) = 28.02 g
    • 6 oxygen x (16.00 g atomic mass) = 96.00 g
      • then take the sum of all the numbers:
      • 40.08 + 28.01 + 96.00 = 164.10 g Ca(NO3)2
    • OR type into the caculator the (# of atoms of the element x atomic mass) +(# of atoms of the element x atomic mass) .....
    • (1 x 40.08) + (2 x 14.01) + (6 x 16.00) = 164.10 gCa(NO3)2
    • See folowing video for more examples:
      • How To Calculate Molar Mass  VIDEO
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    • Recall from unit 1 the following termomlology
      

 

 

• One step stoichiomentry conversions

  • NOTE particle is a general descripition more specific terms may be used
    • Elements are referred to as atoms
    • Covalent compunds are referred to as molecules (mlc)
    • Ionic compunds are referred to as Formula Units (F.U.)
    • Ions are referred to as Ions
  •      

  • ;
  • See videos below for more examples:
    • Converting Between Grams and Moles
    • Moles and Volume Conversion
    • Moles and Particles

 

• After Watching the previous videos go to the following page and attemp a few of the practice items (you will need to scroll down) for both caculating molar mass (part 2 on web page) and doing converions with moles (mole practice problesm on web page).
  • Introduction to the Mole and Molar Mass (optional)

 Make sure to copmlete the introduction to stoichiomentry assignment given out in class today.

If you were abstent one version of this assignent is linked below.

Introduction to Stoichiometry 

 

• SC3. Obtain, evaluate, and communicate information about how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.
  • SC3.c:  Use mathematics and computational thinking to apply concepts of the mole and Avogadro’s number to conceptualize and calculate
  • SC3.c.3:  mass, moles, and molecules relationships
  • SC3.c.4:  molar volumes of gases
  • SC3.d:  Use mathematics and computational thinking to identify and solve different types of reaction stoichiometry problems (i.e., mass to moles, mass to mass, moles to moles, and percent yield) using significant figures.