Bell work • Grab a whiteboard, marker, and eraser. You’ll need it soon. • In your notebook, write the ten prefixes for organic compounds.
Agenda • Bell work • Organic nomenclature overview • Organic practice • Pass out lab books • Begin review of chapter 4 • Homework: • Pre lab questions (due Tuesday), read through lab so you’re prepared for Tuesday • Homework problems (on sheet) due Thursday
Organic Chemistry • The chemistry of carbon compounds. • Carbon has the ability to form long chains. • Without this property, large biomolecules such as proteins, lipids, carbohydrates, and nucleic acids could not form.
Structure of Carbon Compounds • There are three hybridization states and geometries found in organic compounds: • sp3Tetrahedral • sp2 Trigonal planar • sp Linear
Hydrocarbons • Four basic types: • Alkanes • Alkenes • Alkynes • Aromatic hydrocarbons
Alkanes • Only single bonds. • Saturated hydrocarbons. • “Saturated” with hydrogens.
Formulas • Lewis structures of alkanes look like this. • Also called structural formulas. • Often not convenient, though…
Formulas …so more often condensed formulas are used.
Properties of Alkanes • Only van der Waals force: London force. • Boiling point increases with length of chain.
Structure of Alkanes • Carbons in alkanes sp3 hybrids. • Tetrahedral geometry. • 109.5° bond angles.
Cycloalkanes • Carbon can also form ringed structures. • Five- and six-membered rings are most stable. • Can take on conformation in which angles are very close to tetrahedral angle. • Smaller rings are quite strained.
Alkenes • Contain at least one carbon–carbon double bond. • Unsaturated. • Have fewer than maximum number of hydrogens.
Alkynes • Contain at least one carbon–carbon triple bond. • Carbons in triple bond sp-hybridized and have linear geometry. • Also unsaturated.
Nomenclature of Alkynes 4-methyl-2-pentyne • Analogous to naming of alkenes. • Suffix is -yne rather than –ene.
Aromatic Hydrocarbons • Cyclic hydrocarbons. • p-Orbital on each atom. • Molecule is planar. • Odd number of electron pairs in -system.
Aromatic Nomenclature Many aromatic hydrocarbons are known by their common names.
Functional Groups Term used to refer to parts of organic molecules where reactions tend to occur.
Alcohols • Contain one or more hydroxyl groups, —OH • Named from parent hydrocarbon; suffix changed to -ol and number designates carbon to which hydroxyl is attached.
Ethers • Tend to be quite unreactive. • Therefore, they are good polar solvents.
Carbonyl Compounds • Contain C—O double bond. • Include many classes of compounds.
Aldehydes At least one hydrogen attached to carbonyl carbon.
Ketones Two carbons bonded to carbonyl carbon.
Carboxylic Acids • Have hydroxyl group bonded to carbonyl group. • Tart tasting. • Carboxylic acids are weak acids. CH3COOH
Esters • Products of reaction between carboxylic acids and alcohols. • Found in many fruits and perfumes.
Amides Formed by reaction of carboxylic acids with amines.
Amines • Organic bases. • Generally have strong, unpleasant odors.
Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain.
Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain. • Suffix: Tells what type of compound it is.
Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain. • Suffix: Tells what type of compound it is. • Prefix: Tells what groups are attached to chain.
Organic Nomenclature • 2, 3-dimethylpentane • How many carbons are in the main chain? • What do the numbers mean?
Organic Nomenclature • How many bonds can carbon form? • How can you tell how many bonds an atom can form?
To Name a Compound… • Find the longest chain in the molecule. That’s your base • Number the chain from the end nearest the first substituent encountered. • List the substituents as a prefix along with the number(s) of the carbon(s) to which they are attached.
To Name a Compound… If there is more than one type of substituent in the molecule, list them alphabetically.
Sample problems • Going from condensed formula to structural formula • When there are parenthesis, it means that it comes off that specific carbon. It is not a part of the main chain. • Follow nomenclature guidelines
Pass out lab books • In pen, write your name in the front of the book • Do not write in these books otherwise. You will be able to copy tables into your actual lab notebooks. You’ll get these on Tuesday. • Read through lab 1 well enough so you have a solid idea of what you’re going to be doing on Tuesday. Tuesday should not be the first time you read through the lab. • Complete the pre-lab questions. They’re due on Tuesday.
Bell work 9/7 • Turn your pre-lab questions into the tray. • What are some questions you have about the lab? • When you are finished, put your science notebook back. Grab and read a “Techniques for Handling Crucible” hand out.
Agenda • Bell work • Turn in pre-lab questions • Pass out lab notebooks • Overview use of lab notebooks • Lab edits • Homework: • Complete first 5 organic questions (due Thursday) • Work on post-lab questions and analysis (due Tuesday)
Lab notebook • Write your first and last name clearly on the front • BEWARE – these are carbon copy sheets, so use the periodic table pull out to keep from marking on several sheets at once • On the first page, create a table of contents • Skip to page 6 and fill in spaces for name, experiment, date, etc • Refer to my college lab notebooks
Lab edits • You are not going to repeat the experiment. Instead, we are going to pool data. • You would do 3 trials—instead do the lab once and then get data from two other groups • DO NOT WRITE IN THE PINK LAB BOOK • Copy the data table into your fancy lab notebook • Follow the directions outlined in your pink book. Record your actions and observations in your lab notebook.
Lab • Your lab analysis and post-lab questions will be due next week Tuesday. • Make sure you get the data from two other groups, so you can do the full analysis of Trial 1, Trial 2, and Trial 3
Bell work • A compound has 1.534 moles of Fe and 2.045 moles of O. Use the ratio between the number of moles of iron and number of moles of oxygen to calculate the empirical formula of iron oxide.
Agenda • Bell work • Questions over the lab • Chapter 4 • Sample problems throughout • Solubility rules song • Revisit organic • Homework: • Finish organic nomenclature problems • Textbook problems from Chapter 4 (written on top of organic sheet)
Chapter 4 • Aqueous reactions and solution stoichiometry
Solutions: • Homogeneous mixtures of two or more pure substances. • The solvent is present in greatest abundance. • All other substances are solutes. • Solutions in which water is the dissolving medium are called aqueous solutions
Dissociation • When an ionic substance dissolves in water, the solvent pulls the individual ions from the crystal and solvates them. • This process is called dissociation.
Ionic Compounds in Water • Ionic solid dissociates into its component ions as it dissolves • Water is an effective solvent • Oxygen is electron-rich and carries partial negative charge • Hydrogen has a partial positive charge • Polar molecule: uneven distribution of electron density
Imagine preparing two aqueous solutions—one by dissolving a teaspoon of table salt (sodium chloride) in a cup of water and the other by dissolving a teaspoon of table sugar (sucrose) in a cup of water. • How can you tell them apart?