= Chem 1100 Lecture 8 Outline of Last Lecture I. The Greenhouse EffectII. The History of Our AtmosphereIII. Shapes of MoleculesIV. Light & MoleculesOutline of Current Lecture I. Carbon DioxideII. Weighing CarbonIII. Chemical EquationsCurrent LectureI. Carbon Dioxide (Co2)a. Natural Sourcesi. CaCo3 (limestone) dissolves in water, the calcium gets separated, and then carbon dioxide is created.ii. It also comes from plants and animals during respiration or decay. iii. Volcanic vents – a volcano could erupt and the fossil fuels create carbon dioxide.b. Where does it go?i. This happens on a large scale in the ocean. Some of the Co2 could re-react with calcium and make mineral deposits. Then with enough pressure and enough time the mineral deposits can then become fossil fuels. c. Fossil Fuel contribution to atmospheric Co2:i. 6-7 billions tons of carbon released – about half of this goes into the atmosphere.ii. Fossil Fuels: oil, coal, & natural gasiii. 2000 lbs. in 1 tonThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iv. Since 1860 (start of industrial revolution) CO2 concentration has gone up from 290 ppm to 385 ppm. If you were to collect a million random particles from the atmosphere then 290 of them would be carbon dioxide. Its significant enough to cause an increase in temperature. It roughly increases around 1.5 ppm per year since 1860. v. We need Co2 to maintain a temperature on our planet in which we can exist. But we are worried about the runaway greenhouse effect. d. Quantitative Concepts: Mass CO2i. Co2 is a concern, with the increase in the atmosphere. 3.1-3.5 Gt of carbon per year (Gt = billion tons of). How much Co2 is added per year?ii. How much does an atom weight? It depends on the atom.iii. Our standard measurement that we use is Carbon-12. That’s the kind of carbon that has 6 protons and 6 neutrons. The # 12 is the mass number. It’s atomic # 6. iv. Atomic Mass Units. If we have 1 atom of Carbon 12 that atom is going to weigh 12 atomic mass units (amu). 12.01 is the atomic mass. v. Why 12.01 and not 12? 1. 98.89% of carbon atoms on this planet are carbon 12 atoms2. 1.11 % of carbon atoms on this planet are carbon 13 atoms. They have 6 protons and 7 neutrons.3. Approx. 0.00% is carbon 14 atoms. Very long miniscule number with lots of zeros before any other number comes along.4. We can make a weighted average. The average atomic mass of all 3 types of carbon atoms = 12.01 amu. 5. No carbon atoms weight 12.01 amu. 6. Treat all carbon atoms as though they weigh 12.01. But really its just the average.7. 1 tbs of carbon has about 6.022 X 10^23 carbon atoms – whendealing with large numbers of atoms – average is bestII. Weighing Carbon1. Can’t weigh individual atoms2. Define in terms of grams, not amu3. Reference: 12 g of carbon -12 which is about a tablespoor full is going to have 6.02 x 10^23 carbon atoms in it. 4. Avogadro’s number: 6.02 x 10^23 also = 1 mole5. A gross of shoes would be 144 shoes. 144 individual shoes not pairs. 6. Why do we use Avogadro’s number? Ex: the average carbon atom weighs 12.01 atomic mass units/molar mass (in grams).If I have an entire mole of carbon atoms. Then that mole of carbon atoms is going to weigh 12.01 grams. 7. Do you understand molar mass?a. How many atoms are in 0.551 g of potassium (K)?b. K’s average mass is 39.10 amu. An entire mole also equals 39.10 grams. We only have 0.551 g of K a little less than a gramc. 1 mol K = 39.10 g Kd. 1 mol K = 6.022 x 10^23 atoms Ke. = 8.49 X 10^21 atoms Kf. Molecular mass (or molecular weight) is the sum of theatomic masses (in amu) in a molecule. g. Ex: SO2 1S is going to weigh 32.07 amu2O + 2 x 16.00 amuSO2 = 64.07 amuh. How many moles of C3H8O are in 72.5 grams?1 mol C3H8O = (3 x 12) + (8 x 1) + 16 = 60 g C3H8Oi. Molar mass is the mass of 1 mole of eggs/shoes/marbles/atoms in grams.j. 1 mole 12C atoms = 6.022 x 10^23 12C = 12.00 gk. 1 12C atom = 12.00 amul. 1 mole C atoms = 12.01 gm. 1 mole lithium atoms = 6.941 g of LiIII. Chemical Calculationsa. So 1 mol of carbon weighs 12.01 g. 1 mol of Co2 weighs 44.01 g.b.c. If 3.3 Gt of C are put in the air: d.e. Relating this to chemical equations: A chemical reaction is when a substance undergoes a chemical reaction to create a new substance. Chemical bonds are being broken and formed.f. Chemical equation: symbols showing what happens during the reactions.g. 2 Mg (s) + O2 (g)  2 MgO (s)^^Reactant ^^^ Producth. Physical states are sometimes omitted but the equation must always be balanced. i. How to “read” chemical equations j. One way we can interpret this equation would be that we have 1 atoms of Mg and we added 1 molecule of O2 which makes 2 MgO unitsk. Another way: Because of Avogadro’s number 2 moles of Mg will react of 1 mole of O2 to make 2 moles of MgOl. We could convert those moles to grams. 48.6 grams of Mg reacted with 32.0 grams of O2 makes 80.6 g MgOm. DON’T INTERPRET this as take the coefficiants and stick grams behind it. 2 grams of Mg + 1 gram of O2 makes 2 g Mgo  This is