Unit V: The Mole Concept V.3. Multiple Conversions between Moles, Mass, Volume and Number of Particles

THE MIGHTY MOLE DIAGRAM

THE MIGHTY MOLE DIAGRAM grams moles molecules atoms L @STP

Mighty Mole Questions Grams to Molecules conversion How many molecules are in a 2.62 g sample N2O4 Plan: g  mol  molecules 1.71 x 1022 molecules

Mighty Mole Questions Molecules to Litres Conversion Find the volume occupied by 1.204 x 1026 molecules of SO2 at STP? Plan: molecules  moles  L 4480 L

Mighty Mole Questions Grams to Atoms Conversion Find the total number of atoms in a 300.0 g glass of water. Plan: g  mol  molecules  atoms date leaves 3.01 x 1025 atoms

Mighty Mole Questions Grams to Molecules 0.0342 g CH4 = ? Molecules Plan: grams  moles  molecules 1.29 x 1021 molecules

Mighty Mole Questions Litres to Molecules Conversion 54.3 L of NO2 = ? Molecules 1.46 x 1024 molecules

Mighty Mole Questions Molecules to Grams Conversion Find the mass of 3.68 x 1025 molecules of NO2 (g)? 2.81 x 108 grams

Mighty Mole Questions Molecules  Litres (STP) Conversion 1.35 x 1026 molecules of NH3 = ? L at STP 5.03 x 103 L

Mighty Mole Questions Grams to Atoms Conversion Find the number of atoms in a 286.0 g sample of C3H8? 4.30 x 1025 atoms

Mighty Mole Questions Find the number of “O” atoms in a 60.0L sample of N2O4 6.45 x 1024 “O” atoms

Hebden Do Exercises 22 (a); 23 (a-d); 24 on pages 86-87 of Hebden Do Exercises 36 (a); 37 (a) ; 38 (c); 42 (b, h, m) on pages 88-89 of Hebden Assignment #9

DENSITY AND MOLES Density is the mass per unit of volume M D V

THE MIGHTY MOLE DIAGRAM grams moles molecules atoms L @STP

FOR GASES ONLY Density of Gases at STP Density STP = DSTP Mass of 1 mole Volume 1 mole = Molar Mass 22.4 = MM (g/mol) 22.4 (L/mol) FOR GASES ONLY

Density of Gases at STP Find the density of P2O5 gas at STP? DSTP 6.34g/L = MM (g/mol) 22.4 (L/mol)

Density of Gases at STP Calculate the density of O2 (g) at STP? DSTP 1.43 g/L = MM (g/mol) 22.4 (L/mol)

Density of Gases at STP The density of air is about 1.29 g/L. What is the density of Cl2 (g) at STP? DSTP 3.17 g/L  so Cl2 (g) is more dense than air = MM (g/mol) 22.4 (L/mol)

Molar Mass From Density at STP DSTP = MM (g/mol) 22.4 (L/mol) MM = DSTP x 22.4

Molar Mass From Density at STP An oxide of chlorine has a density of 3.013 g/L at STP Find the molar mass of this gas Determine the molecular formula for this gas MM = DSTP x 22.4

Molar Mass From Density at STP An oxide of chlorine has a density of 3.013 g/L at STP 6.75 g/mol MM = DSTP x 22.4

Molar Mass From Density at STP ClO  ClO2 ClO3

Molar Mass From Density at STP A mystery gas has a density of 1.696 g/L at STP. It is an element. Find it’s molar mass 38.0 g/mol MM = DSTP x 22.4

Molar Mass From Density at STP Given the molar mass of 38.0 g/mol Guess the gas

Density of Solids and Liquids WHAT TO DO WHEN YOU DON’T HAVE A GAS!! M = D x V M D V

THE MEGA MIGHTY MOLE DIAGRAM D V D x V grams moles molecules atoms L @STP

Example: Density  Molecules Conversion The density of Boron (solid) is 2.34 g/mL. How many molecules are there in a 60.0 mL chunk of boron? Plan: D x V  g  mol  molecules 7.83 x 1024 molecules of Boron

Example Atoms  Volume Conversion Liquid mercury has a density of 13.55 g/mL. Find the volume occupied by 1.806 x 1027 atoms. (Hg is monatomic) Plan: atoms  molecules mol g volume 44413 mL or 44.4L

Example Moles  Density Conversion A 5.00 mL sample of solid lead is known to contain 0.274 moles of Pb. Calculate the density of Pb. Plan: mol g density 11.35 g/mL

Example: Density  MM (STP) 250.0 mL of a gas which is known to be a fluoride of sulphur has a mass of 1.63 g at STP a) Find the molar mass 146.0g/mol

Example Density  MM (STP) (b) What is the molecular formula for the gas. (Calculated Molar Mass = 146.0g/mol – fluoride of sulphur) SF6 = 146.1 g/mol

Example D  MM (STP) 1.25 L of disilane gas has a mass of 3.47 g. What is the molar mass? (Assume STP) Plan: Density  MM 62.2 g/mol

Example Density  MM (STP) It is found that a 0.0263 mole sample of gas occupies a volume of 482.0 mL. Calculate the molar volume in L/mol. 18.33 L/ mol

Hebden Do Exercises 25, 27, 28 and 29 on pages 88 of Hebden Do Exercises 40 (e), 41 (a, f, h, k), 42 (b, e, n) on pages 89 of Hebden Do Hand-In Density Worksheet

Mid-Unit Test Mega Mighty Mole Diagram Mole Conversions