Identify the Representative Particle Aluminum hydrogen sulfide Sodium chloride Aluminum sulfate Sulfur dioxide sodium Hydrogen

Identify the Representative Particles answers Aluminum Al atoms H2S molecules hydrogen sulfide Sodium chloride NaCl fu’s Al2(SO4)3 fu’s Aluminum sulfate Sulfur dioxide SO2 molecules sodium Na atoms Hydrogen H2 molecules

Using Mole Calculations Mass to Mol

Mass to Mole Use Molar Mass (g/mol) = MM (note: mol/g = 1/MM) ( substance g) X mol g X 1 MM g mol Mass divided by Molar Mass = Moles

Mole to Mass Use Molar Mass (g/mol) = MM ( substance mol) X mol X MM g Moles multiplied by Molar Mass = Grams

Summary Molar Mass = MM Mass to Mol: Divide by MM Mol to Mass: Multiply by MM g MM mol X MM

Avogadro’s Principle Equal volumes of different gases at the same T & P will contain the same number of particles Same # of He atoms as oxygen molecules He O2 Same temperature & pressure

Molar Volume He O2 32.0 g 4.0 g Avogadro 1811 One Mole of a gas at STP will occupy 22.4 L STP = standard temp & pressure 0oC and 1 atm 22.4 L He O2 32.0 g 4.0 g

What is the volume of 38 g of fluorine gas at STP? ANS 22.4 L

What is the volume of 10.09 g of neon at STP? How many mol of Ne is this? 0.50 mol If 1 mol would occupy 22.4 L what volume would this sample occupy? ANS: 11.2 L (or ½ of what 1 mol occupies)

Summary mol to volume conversions for gases X 22.4 mol Vol (L) 22.4