Unit: Chemical Quantities Day 2 - Notes Unit: Chemical Quantities Measuring Mass with the Mole
After today, you will be able to… Calculate molar mass of a substance Use molar mass to calculate the mass of a substance given then number of moles and vice versa
Atomic Mass vs. Molar Mass The atomic mass on the Periodic Table is the mass of a single atom in amu (atomic mass units). Example: 1 carbon atom= 12.01 amu
Atomic Mass vs. Molar Mass The molar mass (MM) = mass of one mole of a substance. It is equal to the atomic mass in grams. Example: 1 mole of carbon atoms = 12.01 grams
Molar Mass Examples Example: What is the molar mass of Al2S3? 53.96 Round molar masses two decimal places to the right! +96.21 150.17g Al2S3=1 mol Al2S3
Molar Mass Examples Example: What is the molar mass of Ba3(PO4)2? 411.99 61.94 +128.00 601.93g Ba3(PO4)2=1 mol Ba3(PO4)2
Example: What is the mass of 1.33 moles of Ba3(PO4)2? K: 1.33 mol Ba3(PO4)2 U: ? g Ba3(PO4)2 1.33 mol Ba3(PO4)2 601.93g Ba3(PO4)2 . x = 1 1 mol Ba3(PO4)2 801g Ba3(PO4)2
Example: How many moles are equal to 157.8g of CaCl2? K: 157.8 g CaCl2 1Ca = 1(40.08) = 2 Cl = 2(35.45) = 40.08 U: ? mol CaCl2 +70.90 110.98 157.8 g CaCl2 1 mol CaCl2 . x = 1 110.98 g CaCl2 1.422 mol CaCl2
Time to Practice! Complete WS 2 HOMEWORK: Time to Practice! Complete WS 2