Chemical Quantities

Moles

• Defined as the number of carbon atoms in exactly 12 grams of carbon-12
• Avogadro's number
• 1 mole=6.02 x 10^23

Molar Mass

• Molar Mass: the mass of one mole is the atomic mass of an element in grams
• to measure the mass of a mole of a compound, add up the individual molar masses

STP

• standard temperature and pressure
• 0 degrees Celsius and 1 atm pressure
• 1 mole=22.4 L of any gas at STP

Calculating Percent composition of a compound

• part/whole x 100%
• First find the mass of each of the compounds
• Then, Divide by the total mass of the compound and multiply by 100

Stoichiometry

• Greek for measuring elements
• The calculations of quantities in chemical reactions