Presentation on theme: "All Roads Lead to the Mole"— Presentation transcript:
1All Roads Lead to the Mole CHEMICAL QUANTITIESAll Roads Lead to the Mole
2Chemical Quantities Dozen: Baker as Mole: Chemist Measuring donuts: 1 dozen = 12 donuts (count)1 dozen = 500 g donuts (mass)1 dozen = 1 box donuts (volume)Measuring steam (H2O gas):1 mole = 6.02 x 1023 H2O molecules (count)1 mole = 18.0 g H2O (mass)1 mole = 22.4 L H2O (volume) at STP
3Count Amedeo Avogadro 1776-1856 Lawyer who became interested in math and physicsDiscovered that equal volumes of different gases contained an equal number of particles.9 years after his death, Joseph Loschmidt determined a constant and named it after Avogadro.
4Not to be confused with the delicious fruit AVOGADRO’S CONSTANT = 6.02 x 1023Not to be confused with the delicious fruit
5AVOGADRO’S CONSTANT = 6.02 x 1023 1 mole = 6.02 x 1023 particles1 mole = molar mass (grams)1 mole (of a gas at STP) = 22.4 L
8Believe it or not, students all over the country celebrate National Mole Day! National Mole Day Foundation, INC.Mole Day
9How BIGis a MOLE?5 Pound Bag of Sugar contains 6.6 moles Of C12H22O111 Liter bottle of Water contains 55.5 moles H206.02 x 1023 Grains of Sand: Would be more than all of the sand on Miami Beach.6.02 x 1023 Blood Cells: Would be more than the total number of blood cells found in every human on earth.6.02 x 1023 Watermelon Seeds: Would be found inside a melon slightly larger than the moon.6.02 x 1023 Pennies: Would make at least 7 stacks that would reach the moon.6.02 x 1023 Donut Holes: Would cover the earth and be 5 miles (8 km) deep.
10...AND YOUR UNITS WILL CARRY YOU! Draw on NOTETAKERS (and pass out flow Mole Map)CARRY YOUR UNITS...VolumeMassMOLER.P.Formula UnitsIonsMoleculesAtoms...AND YOUR UNITS WILL CARRY YOU!
11Types of Representative Particles Molecules (break down into atoms)AtomsFormula Units (break down into ions)Ions
12Naming Representative Particles Pure SubstanceElementMonotomicChargedIONNeutralATOMPolyatomicMOLECULECompoundMolecularIonicFORMULAUNIT
13Naming Representative Particles Examples: Name the representative particle for each substance given. For each molecule, state how many atoms are present. For each formula unit, state how many ions make up the ionic compound.H+:Cl2:C2H6:Cu(NO3)2:Al:NaCl:IONMOLECULE – 2 ATOMS per moleculeMOLECULE – 8 ATOMSFORMULA UNIT – 3 IONS per Form.U.ATOMFORMULA UNIT – 2 IONS per Form.U.
20MOLAR MASSThe molar mass is the mass, in grams, of one mole (6.02 1023 particles) of an element (ion), a covalent molecule or a formula unit.molar mass (MM) gram atomic mass (gam) molecular weight (MW) gram molecular mass (gmm)formula mass (FM) gram formula mass (gfm)formual weight (FW)
21MASS of one MOLEGram atomic mass (gam): the atomic mass (the mass in one mole of a substance) of an element expressed in grams.Gram molecular mass (gmm): the atomic mass of one mole of a molecular compound.Gram formula mass (gfm): the sum of the atomic masses of the atoms that are in the formula of a compound.
22gam, gfm, gmm examples:Problem: Give the gram atomic mass of hydrogen.Solution: H = 1H = 1(1.01) = 1.01 g/molProblem: Give the gram molecular mass of hydrogen.Solution: H2 = 2H = 2(1.01) = 2.02 g/molProblem: Find the gram formula mass for H2SO4.Solution: H2SO4 = 2H + 1S + 4O= 2(1.01) (16.00) = g/mol
23Molar Mass … a.k.a. Molecular Weight (MW) molar mass = mass of 1 mole of substanceMolar mass can be determined by adding up the atomic masses from the periodic table (atomic mass goes to 2 decimal places).
24MW Example 1: = 1C + 4H = 12.01 + 4(1.01) = 16.05 g CH4/mol CH4 Find the MW of CH4.= 1C + 4H= (1.01)= g CH4/mol CH4
25MW Example 2: =Mg + 2O + 2H =24.31 + 2(16.00) + 2(1.01) Find the MW of Mg(OH)2.=Mg + 2O + 2H= (16.00) + 2(1.01)=58.33 g Mg(OH)2 /mol Mg(OH)2
26MW Example 3: Find the MW of MgSO4∙7H2O. =Mg + S + 4O + 7(H2O) = (16.00) + 7( )= g MgSO4∙7H2O /mol MgSO4∙7H2O
28Mole Mass Calculations 1 mole = molar mass (MW) in gramsMassMOLE
29Mass Example 1:How many grams are in 7.20 moles of dinitrogen trioxide?dinitrogen trioxide = N2O3MW of N2O3 = 2N + 3O = 2(14.01) + 3(16.00) = g/mol1 mole = g N2O3
30MW of Fe2O3 = 2Fe + 3O = 2(55.85) + 3(16.00) = 159.70 g/mol Mass Example 2:Find the number of moles in 92.2 g of iron(III) oxide.iron(III) oxide = Fe2O3MW of Fe2O3 = 2Fe + 3O = 2(55.85) + 3(16.00) = g/mol1 mole = g Fe2O3
31Make sure you write out all work and include all units!! Practice WorksheetDo #1-10 on Mole and Mass WSMake sure you write out all work and include all units!!
32Mole Volume Calculations 1 mole = 22.4 L of gas at STPSTP = standard temperature and pressure (0 °C & 1 atm)VolumeMOLE
33Volume Example 1:Determine the volume, in liters, of mol of SO2 gas at STP.
34Volume Example 2:Determine the number of moles in 33.6 L of He gas at STP.
35Density density = mass / Volume When given the density of an unknown gas, one can multiply by the molar volume to find the MW.The MW can allow for identification of the gas from a list of possibilities.
36Density Example (part A): The density of an unknown gas is g/L at STP. (a) What is the molar mass?
37Density Example (part B): The density of an unknown gas is g/L (b) Identify the gas as either nitrogen, fluorine, nitrogen dioxide, carbon dioxide, or ammonia.MW = g/mol (from part a)Nitrogen = N2 = 2(14.01) = g/molFluorine = F2 = 2(19.00) = g/molNitrogen dioxide = NO2 = (16.00) = g/molCarbon dioxide = CO2 = (16.00) = g/molAmmonia = NH3 = (1.01) = g/mol
38Mixed Mole Conversions 1 mole = x 1023 RP’s = MW = L ofAll Roads Lead to the Mole.Always convert to units of moles first when converting between grams, liters, and representative particles.
39Mixed Mole Example 2: How many atoms are in 22.0 g of water? 22.0 g H2O × 1 mole H2O g H2O × 6.02×1023 molec. H2O 1 mole H2O × 3 atoms 1 molec. H2O
40Mixed Mole Example 1:How many carbon atoms are in a 50.0-carat diamond that is pure carbon? Fifty carats is the same as 10.0 g.