6Atom are small Really small Gold Atomic Force Microscope (AFM) that can simultaneously map surface topography and measure the "dragging" or frictional force of the tip as it scans across a surface.
7Atomic Masses: Counting by Weighing Atomic Mass Units amuOnly used for atomsVery Small!!1 amu = 1.66 x gMass number units on periodic table:amu1 atom
8Atomic Masses: Counting by Weighing We need a reasonable number to weigh atomsAvogadro ( )Avogadro's Hypothesis: equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.He also proposed that oxygen gas and hydrogen gas were diatomic molecules.
10Mole Facts6.02 X 1023 Watermelon Seeds: Would be found inside a melon slightly larger than the moon.6.02 X 1023 Donut Holes: Would cover the earth and be 5 miles (8 km) deep.6.02 X 1023 Pennies: Would make at least 7 stacks that would reach the moon.
11Mole Facts6.02 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 C02 Molecules: Would be found in 1 Mole Balloon TM at STP.1 Liter bottle of Water contains 55.5 moles H20
12Mole Facts 5 Pound Bag of Sugar contains 6.6 moles of C12H22O11 1 Mole BalloonTM: Contains 22.4 Liters of any gas at STP.There are 3 types of moles that live underground in North America: Eastern Mole, Hairy-Tailed Mole and Star-Nosed MoleThe "Mexican" Mole: Is a chocolate sauce or turkey stew. It comes from the Aztec word "molli." For recipes go to Web Hangouts.
19Calculating Mass from Moles What is the mass of 4.86 mol of CaCO3?Molar Mass of CaCO3?1 mol Ca = 1 x g = g1 mol C = 1 x g = g3 mol O = 3 x g = gMolar mass of CaCO3 = g/mol
20Calculating Mass from Moles Molar mass of CaCO3 = gWhat is the mass of 4.86 mol of CaCO3?4.86 mol CaCO3 x g = ?mol= 486 g CaCO3
21Moles from Mass How many moles is 1.56 g of juglone? Juglone is a dye used for centuries that produced from black walnut trees. It is also a natural herbicide.Formula = C10H6O3Find Molar Mass of juglone174.1 g/mole
22Moles from Mass 1mol = 174.1 g of juglone 1.56 g juglone x 1 mol juglone =?174.1 gmol juglone8.96 x 10-3 mol juglone
24Percent Composition of Compounds Percent by massPercent = x 100%Mass fractionof a given =elementPartWholeMass of element present in 1 mol of compoundMass of 1 mol of compound
25Percent by Mass of Each Element in PVC, C2H3Cl 2 mol C atoms = 2 x = g3 mol H atoms = 3 x = g1 mol Cl atoms = 1 x = g= g/mol% C = x 100% = % C% H = x 100% = % H% Cl = x 100% = % Cl24.02 g62.494g3.024 g62.494g35.45 g62.494g% Total to check
27Percent by Mass Price E.L. Fudge original $3.09 24 Famous Amos Vanilla Number of Cookies/PackageE.L. Fudge original$3.0924Famous Amos Vanilla$2.5945Dunksters Double Crème$2.9938Value Time Peanut Butter$2.0954
28Mole Day, March 20, 2008Celebrated annually on October 23 from 6:02 a.m. to 6:02 p.m., Mole Day commemorates Avogadro's Number (6.02 x 1023), which is a basic measuring unit in chemistry. For second term, we are celebrating on March 20th.Mole Day was created as a way to foster interest in chemistry. Schools throughout the United States and around the world celebrate Mole Day with various activities related to chemistry and/or moles.
29Mole Day, March 20, 2008For a given molecule, one mole is a mass (in grams) whose number is equal to the atomic mass of the molecule. For example, the water molecule has an atomic mass of 18, therefore one mole of water weighs 18 grams. An atom of neon has an atomic mass of 20, therefore one mole of neon weighs 20 grams.In general, one mole of any substance contains Avogadro's Number of molecules or atoms of that substance. This relationship was first discovered by Amedeo Avogadro ( ) and he received credit for this after his death.
30Extra Credit Mole Day Projects Make Mole Day treats to share:Moleasses cookies, Avogadro Dip, Mole Cake, Guacamole or Taco-mole sauceMake an object of “mole” artCreate a “Moletin” Board or posterWrite a Mole Day poem or song to perform for the classCreate a “Mole-opoly” gameCreate mole day flag or costumeCreate a mole day T-shirt (5-points maximum)Make a mole piñata or a stuffed mole
31Extra Credit Mole Day Projects 0 to 20 points extra credit are possible. Points given will be based on effort and creativity and added to your homework grade.You may do more than one project BUT you may receive a maximum of 20 points.There is no make-up or late projects allowed.
34Empirical Formula of a Compound Converting masses measured in laboratory to chemical formulasNeed to convert gram to moles and then develop an empirical formulaEmpirical Formula – the formula of a compound that expresses the smallest whole-number ratio of the atoms present.Molecular Formula – the actual formula of the compound.
35Determining the Empirical Formula of a Compound (p. 179) Step 1 - Obtain the mass of each elementConsider g of the compound.33.88% Cu = g Cu14.94% N = g N51.18% O = g O
36Determining the Empirical Formula of a Compound (p. 179) Step 2 - Determine the number of moles of each element33.88 g Cu x = mol Cu14.94 g N x = mol N51.18 g O x = mol O1 mole63.55 g1 mole14.01 g1 mole16.00 g
37Determining the Empirical Formula of a Compound (p. 179) Step 3 - Divide the number of moles of each element by the smallest number of moles to convert the smallest number to
38Determining the Empirical Formula of a Compound (p. 179) Step 3 continued - If all the number are integers (whole numbers), they are the subscripts in the empirical formula.If one or more of these numbers are not integers, go to Step 4.The empirical formula is CuN2O6[i.e., Cu(NO3)2]
39Determining the Empirical Formula of a Compound (p. 179) Step 4 – Multiply the numbers you derived in step 3 by the smallest number that will convert all of them to whole numbers. This set of numbers represents the subscripts in the empirical formula.
40Empirical Formula of a Compound C6H12O6 = CH2OC6H6 = CHNa2O2 = NaO