Presentation on theme: "Quantitative Chemistry Block 6 Zachary Baillie Ryan Gerhart Patrick McGay Sheel Patel."— Presentation transcript:
Quantitative Chemistry Block 6 Zachary Baillie Ryan Gerhart Patrick McGay Sheel Patel
Summary Quantitative chemistry is based on the Law of Conservation of Mass.
Formula Mass Is the atomic weight in grams Is also called the “relative atomic mass” and “molecular mass” Examples: Hydrogen Gas H2, the formula mass is 2.0158 g=(2*1.0079) Mass of O2 is about 32 g=(2*15.9994)
Formula Mass of Compounds The formula mass of a compound equals the sum of the formula masses of it’s components For CaCl2- Ca=40.08 g Cl=2*43.35=90.870 g Total=130.95 g For glucose(C6H12O6)- C=6*12.0107=72.0642 g H=12*1.00794=12.09528 g O=6*15.9994=95.9964 g Total=72.0642+12.09528+95.9964=80.1559
Mass of Molecule The molecular mass is the standard unit for measuring chemicals Chemists call this a “mole” One mole of a substance contains about 6.02x10^23 This is Avogadro’s Number, L
Calculating the Number of Moles Moles= measured mass/formula mass If we have 458.325 g. of CaCl(2), how many moles do we have? Moles= 458.325/(130.95 g/mole)= 3.5 moles