Chemistry 121

Chemistry 121Chemistry 121

Dr. Patrick WoodwardDr. Patrick Woodward

Office Office 3109 Newman and Wolfrom Lab3109 Newman and Wolfrom Lab

Office Hours Office Hours 2:30-3:30 M, T, W, R2:30-3:30 M, T, W, R

E-mail E-mail [email protected]

Phone Phone 688-8274688-8274

Web Site Web Site www.chemistry.ohio-state.edu/~woodward/www.chemistry.ohio-state.edu/~woodward/chem_121.htmchem_121.htm

mailto:[email protected]

Chemistry 121Chemistry 121

Required MaterialsRequired Materials

Text Text “Chemistry, The Central Science” by Brown, “Chemistry, The Central Science” by Brown, Lemay and Bursten 9Lemay and Bursten 9thth Edition Edition

Lab Manual Lab Manual “General Chemistry Laboratory “General Chemistry Laboratory Experiments, Volume 1” by Casey & Experiments, Volume 1” by Casey & TatzTatz

Lab Notebook Lab Notebook “Student Laboratory Notebook” “Student Laboratory Notebook”

Calculator Calculator TI-30, Sharp EL-509, Sharp EL-531, TI-30, Sharp EL-509, Sharp EL-531, Casio FX-250Casio FX-250

www.chemistry.ohio-state.edu/~woodward/www.chemistry.ohio-state.edu/~woodward/chem_121.htmchem_121.htm

Grading SchemeGrading SchemeMidterm 1 (Tues, Feb 3Midterm 1 (Tues, Feb 3rdrd) ) 175 pts 175 pts

Midterm 2 (Tues, Feb 24Midterm 2 (Tues, Feb 24thth) ) 175 pts175 pts

Final Exam (Tues, Mar 16Final Exam (Tues, Mar 16thth) ) 300 pts300 pts

Laboratory (10 labs)Laboratory (10 labs) 200 pts200 pts

Quizzes Quizzes (6 Quizzes, drop the lowest)(6 Quizzes, drop the lowest) 150 pts150 pts

Total Total 1000 pts1000 pts

Opportunities to do problemsOpportunities to do problems Take home quizzesTake home quizzes Recitation ExercisesRecitation Exercises Homework Problems (at the end of the chapter)Homework Problems (at the end of the chapter) Web Material (Old exams, sample quizzes, CD Web Material (Old exams, sample quizzes, CD

exercises)exercises)

Top 5 Myths about Chem Top 5 Myths about Chem 121121

5. This class is a weed out class.5. This class is a weed out class.

For example consider the final grade distribution For example consider the final grade distribution from Autumn 2002 (beginning with ~300 students):from Autumn 2002 (beginning with ~300 students):

21 Dropped21 Dropped 20 Failed20 Failed

29 D/D+29 D/D+ 126 C-/C/C+126 C-/C/C+

59 B-/B/B+59 B-/B/B+ 46 A-/A46 A-/A


4. It’s OK to blow off lab, because it’s only 20% of 4. It’s OK to blow off lab, because it’s only 20% of your grade.your grade.

If you don’t get 50% in lab, you will be given a failing If you don’t get 50% in lab, you will be given a failing grade. Extra time will not be given to make up grade. Extra time will not be given to make up missed labs.missed labs.


3. The curve will save me.3. The curve will save me.

If you get below 600 points (60%) the best grade you 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+.can hope for is C-, and your likely to get a D or D+.

If you get below 500 points (50%) you’re almost If you get below 500 points (50%) you’re almost certain to fail the class.certain to fail the class.


2. There are so many students that office hours will 2. There are so many students that office hours will be very crowded, plus professors don’t want to be be very crowded, plus professors don’t want to be bothered.bothered.

Office hours are usually only crowded before the Office hours are usually only crowded before the exams. I set aside time to see you during office exams. I set aside time to see you during office hours so it’s boring when no one comes. I’m also hours so it’s boring when no one comes. I’m also happy to make appointments for other times if you happy to make appointments for other times if you have conflicts with my office hours.have conflicts with my office hours.


1. Knowledge of chemistry will make you more 1. Knowledge of chemistry will make you more attractive to the opposite sex and enhance your attractive to the opposite sex and enhance your love life.love life.

Unfortunately based on personal experience I see Unfortunately based on personal experience I see no evidence for this kind of cause and effect no evidence for this kind of cause and effect relationship.relationship.

Scientific MethodScientific Method

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.

Classification & Properties of Classification & Properties of MatterMatter

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.

Elements, Compounds & MixturesElements, Compounds & Mixtures

Pure Substance Matter 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.

Periodic Table

Ne N2

SO3 Homogeneous Mixture

Homogeneous & Heterogeneous Homogeneous & Heterogeneous MixturesMixtures

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 Mixture Composition and properties are non-uniform.

Chocolate Chip Cookie – Chocolate, Dough, etc.

Concrete – Cement, Rocks, etc.

Vomit – Depends upon previous intake of food and drink

Chemical and Physical PropertiesChemical and Physical Properties

Physical Properties The identifying characteristics of matter. Some properties can be readily measured with our senses, such as odor and color, instruments are needed to measure other properties, such as electrical resistivity, compressibility, hardness, melting point, etc.

Chemical Properties Describe the reactivity of a substance toward other substances. Examples include:

Ethanol burns in air (reacts with oxygen in the air)

Sodium reacts vigorously with water,

Corrosion of metal parts (rust),

Trinitrotoluene (TNT) is explosive,

Lysergic acid diethylamide (LSD) is a hallucinogenic drug.

EthanolStoichiometry = C2H6O

Melting Point = -115 ºCBoiling Point = 78 ºCDensity = 0.79 g/cm3

Chemical Prop. = Intoxicating

Ethylene GlycolStoichiometry = C2H6O2

Melting Point = -16 ºCBoiling Point = 197 ºCDensity = 1.11 g/cm3

Chemical Prop. = Toxic

Dimethyl EtherStoichiometry = C2H6O

Melting Point = -140 ºCBoiling Point = -24 ºCDensity = GasChemical Prop. = Intermediate

SI (Metric) UnitsSI (Metric) Units

Metric PrefixesMetric Prefixes

You will be expected to know these prefixes from memory.

Significant FiguresSignificant Figures1. Non-zero numbers are always significant.

2. Zeros between non-zero numbers are always significant.

3. Zeros before the first non-zero digit are not significant. (Example: 0.0003 has one significant figure.)

4. Zeros at the end of the number after a decimal place are significant.

5. Zeros at the end of a number before a decimal place are ambiguous (e.g. 10,300 g).

Significant Figures & Significant Figures & CalculationsCalculations

Addition and SubtractionAddition 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 DivisionMultiplication and Division

The answer cannot have more significant figures than the measurement with the fewest number of significant figures.

Precision and AccuracyPrecision and Accuracy

Units of VolumeUnits of Volume

1 m3 (1003 cm3)/(1 m3) = 1,000,000 cm3

1,000,000 cm3 = 1 106 cm3

Periodic TablePeriodic Table

Chemical ReactivityChemical Reactivity

2H2(g) + O2(g) 2H2O(g)

Documents

Chemistry 121