1. Moles to Mass

2. Calculating Molar Mass Calculate the mass of 1 mole of Carbon Dioxide (CO 2 ) M CO 2 = 12.01 g/mol + 2(16 g/mol) = 44 g/mol

3. Molar mass Triangle m n M Mass (g) Number of molesMolar mass g/mol

4. Moles to Mass Moles (mol)  x molar mass  mass (g) A flask contains 0.750 mol of carbon dioxide, CO 2. What mass of carbon dioxide gas is in this sample? m = n x M CO 2 = 0.750 mol x 44 g/mol = 33.0 g The mass of 0.75 mol of carbon dioxide is 33.0 g

5. Mass to Moles Mass (g)  / molar mass  mol How many moles of acetic acid, CH 3 COOH, are in 23.6 g The molar mass of CH 3 COOH is (12.01 x 2) + (16.00 x 2) + (1.01 x 4) = 60.06g n = m/M CH 3 COOH = 23.6g/60.06 g/mol = 0.393 mol There are 0.393 mol of acetic acid in 23.6 g of acetic acid.

6. Combining # of particles and molar mass Calculate the total number of formula units in 676 g of Ca 3 (PO 4 ) 2 Step 1: Find the molar mass Molar mass of Ca 3 (PO 4 ) 2 = 3(40.08) + 2(30.97) + 8(16.00) =310.18 g/mol

7. Step 2: Find the number of moles n=m/M = 676g/310.18g/mol = 2.17 mol

8. Step 3: Determine the number of formula units N = nN A = (2.17 mol)(6.02 x 10 23 form.units/mol) = 1.31 x 10 24 formula units