Measuring Matter Today you’ll need: Periodic Table Calculator The Mole: Basic Concepts Measuring Matter Today you’ll need: Periodic Table Calculator Note taking materials

Do a dozen eggs weigh the same as a dozen feathers? The Mole: Basic Concepts The Mass of a Mole Do a dozen eggs weigh the same as a dozen feathers? Nope! Does a mole of one element weigh the same as a mole of a different element? Nope!

Molar mass: The mass in grams of one mole of any pure substance. The Mole: Basic Concepts The Mass of a Mole Molar mass: The mass in grams of one mole of any pure substance. atomic mass (g) molar mass = 1 mol

The Mass of a Mole Carbon. Atomic mass: 12.011 amu The Mole: Basic Concepts The Mass of a Mole Carbon. Atomic mass: 12.011 amu Molar mass: 12.011g/mol Manganese Atomic mass: 54.94 amu Molar mass: 54.94 g/mol

Molar mass of a compound The Mole: Basic Concepts Molar mass of a compound Molar mass of a compound: the mass of a mole of the compound. Molar mass of NH3 = molar mass of N + 3(molar mass of H) Molar mass of NH3 = 14.007 g/mol + 3(1.008 g/mol) = 17.031 g/mol

Practice: Finding Molar Mass Find the molar mass of the following: NaOH C2H5OH Sr(NO3)2 (NH4)3PO4 40.00 g/mol NaOH 46.07 g/mol C2H5OH 211.64 g/mol Sr(NO3)2 40.00 g/mol (NH4)3PO4

Examples Molar mass as a conversion factor a) Calculate the mass of 0.625 moles of calcium. 0.625 mol Ca 40.078 g Ca = 25.0 g Ca 1 mol Ca Use molar mass to convert mol to g

Examples Molar mass as a conversion factor b) A roll of copper wire has a mass of 848 g. How many moles of copper are in the roll? 848 g Cu 1 mole Cu = 13.3 mol Cu 63.546 g Cu Use molar mass to convert g to mol

Moles of a compound to Mass The Mole: Basic Concepts Moles of a compound to Mass c) Example: What is the mass of 2.50 moles of (C3H5)2S ? Molar Mass: 114.21 g/mol (C3H5)2S 2.50 mol (C3H5)2S 114.21 g (C3H5)2S = g (C3H5)S 285.3 1 mol (C3H5)2S Use molar mass to convert mol to g

Converting Mass of a Compound to Moles The Mole: Basic Concepts Converting Mass of a Compound to Moles d) How many moles of water are in 1.000 kg of water? Molar Mass: 18.015 g/mol H2O 1.000 kg H2O 1000 g H2O 1 mol H2O = 55.51 mol H2O = mol H2O 18.015 g H2O 1 kg H2O Convert kg to g Use molar mass to convert g to mol

Practice Convert to moles: 1) 25.5 g Ag 2) 300.0 g S 3) 319 g H2SO4 Convert to grams: 4) 3.57 mol Al 5) 42.6 mol Si 6) 4.35x10-2 mol ZnCl2 0.236 mol Ag 96.3 g Al 9.355 mol S 1.2x103 g Si 3.25 mol H2SO4 5.93 g ZnCl2