Chemistry 121. Dr. Patrick Woodward Office 3109 Newman and Wolfrom Lab Office Hours 2:30-3:30 M, T, W, R E-mail [email protected] Phone 688-8274 Web Site www.chemistry.ohio-state.edu/~woodward/chem_121.htm. Chemistry 121. Required Materials
Text “Chemistry, The Central Science” by Brown, Lemay and Bursten 9th Edition
Lab Manual “General Chemistry Laboratory Experiments, Volume 1” by Casey & Tatz
Lab Notebook “Student Laboratory Notebook”
Calculator TI-30, Sharp EL-509, Sharp EL-531, Casio FX-250
5. This class is a weed out class.
For example consider the final grade distribution from Autumn 2002 (beginning with ~300 students):
21 Dropped 20 Failed
29 D/D+ 126 C-/C/C+
59 B-/B/B+ 46 A-/A
4. It’s OK to blow off lab, because it’s only 20% of your grade.
If you don’t get 50% in lab, you will be given a failing grade. Extra time will not be given to make up missed labs.
3. The curve will save me.
If you get below 600 points (60%) the best grade you can hope for is C-, and your likely to get a D or D+.
If you get below 500 points (50%) you’re almost certain to fail the class.
2. There are so many students that office hours will be very crowded, plus professors don’t want to be bothered.
Office hours are usually only crowded before the exams. I set aside time to see you during office hours so it’s boring when no one comes. I’m also happy to make appointments for other times if you have conflicts with my office hours.
1. Knowledge of chemistry will make you more attractive to the opposite sex and enhance your love life.
Unfortunately based on personal experience I see no evidence for this kind of cause and effect relationship.
Keep in mind though that generally hypotheses and even theories are based on an incomplete set of experiments, so that later experiments or advances may provide further information that shows the theory or hypothesis to be incorrect.
Matter – Anything that has mass and occupies space.
Atom – The smallest stable building block of matter. Made up of protons, neutrons & electrons.
Molecule – Groups of atoms held together with a specific connectivity and shape.
Composition tells us the types of atoms that are present in a compound and the ratio of these atoms (for example H2O, C2H6O, etc.).
Structure tells us which atoms are connected (bonded) to each other, how far apart they are, and the shape of the molecule.
Pure SubstanceMatter that has a fixed composition and distinct properties. All substances are either elements or compounds.
Elements All atoms are the same, i.e. Oxygen (O2), Gold (Au), Silicon (Si) and Diamond (C).
You should memorize the elemental symbols in Table 1.2
Compounds Contains more than one type of atom, but all molecules (or repeat units) are the same, i.e. Water (H2O), Ethanol (C2H6O), Quartz (SiO2), Sodium Chloride (NaCl). All compounds follow the law of constant composition.
Mixture Have variable composition and can be separated into component parts by physical methods. Mixtures contain more than one kind of molecule, and their properties depend on the relative amount of each component present in the mixture.
Homogeneous Mixture Composition and properties are uniform. Sometimes called a solution.
Air – principle components include O2, N2 & CO2
Vodka – principle components are ethanol and water
Brass – solid solution of Cu and Zn
Ruby – solid solution of Al2O3 and Cr2O3
Heterogeneous MixtureComposition and properties are non-uniform.
Chocolate Chip Cookie – Chocolate, Dough, etc.
Concrete – Cement, Rocks, etc.
Vomit – Depends upon previous intake of food and drink
Stoichiometry = C2H6O
Melting Point = -115 ºC
Boiling Point = 78 ºC
Density = 0.79 g/cm3
Chemical Prop. = Intoxicating
Stoichiometry = C2H6O
Melting Point = -140 ºC
Boiling Point = -24 ºC
Density = Gas
Chemical Prop. = Intermediate
Stoichiometry = C2H6O2
Melting Point = -16 ºC
Boiling Point = 197 ºC
Density = 1.11 g/cm3
Chemical Prop. = Toxic
You will be expected to know these prefixes from memory.
Addition and Subtraction
Line up the numbers at the decimal point and the answer cannot have more decimal places than the measurement with the fewest number of decimal places.
Multiplication and Division
The answer cannot have more significant figures than the measurement with the fewest number of significant figures.
1 m3 (1003 cm3)/(1 m3) = 1,000,000 cm3
1,000,000 cm3 = 1 106 cm3
2H2(g) + O2(g) 2H2O(g)