Study guide for IB Chem III test: OrganicsMade by Brittanie Esty; Appendix by Autumnah

Things you just need to know that are difficult to type:

1.) How to draw Alkanes, Alkenes, Alkynes, and all the funky functional groups she gave us on the sheet she gave us forever and a day ago.2.) How to name things from drawings.3.) Know the general formulas for functional groups, i.e. an ester is R-O-R.

NOTE: Study ALL of the quizzes we have taken!!!!!!

The following things are the revised answers from the Yellow Sheet:

1.) A homologous series is a series of molecules with a general formula and differ by a constant between each molecule, i.e. CH4, C2H6, and C3H8 all differ by –CH2 and have a general formula of CxH(2x+2). They have similar chemical properties and a gradual change in physical properties down the series.

2.) A: As a straight chain gets longer, the mass becomes greater and London Dispersion forces become stronger, thus the boiling point rises because it takes more energy to overcome the intermolecular forces (London Dispersion). B: As the chains become more spherical (or branched), the surface area decreases and the intermolecular forces become weaker. This lowers the boiling point because less energy is required to overcome the intermolecular forces.

3.) Alkanes have relatively high bond energies within their C-C and C-H bonds. This makes it difficult to break these bonds and react under normal conditions. So alkanes are inert because it takes a lot of energy to overcome the INTRAmolecular forces of the CC and CH bonds.

Note: Alkanes will react under UV light, with Halogens, and combustion with oxygen.

4.) All of these are Exothermic, but the energy released decreases down this series.

Sufficient O2: CH4 + 2O2 CO2 + 2H2O

Insufficient O2: CH4 + 3/2 O2 CO + 2H2O

Really insufficient O2: CH4 + O2 C (solid) + 2H2OThis rxn produces soot

5.) This was really hard to type, but ALL of these are on the sheet, in our notes, in the IB Chem book, and the Organic Chem book!

6.) Another difficult one to type…sorry guys!

7.) Structural Isomers: Same molecular formula, but with different structural formulas

these have different physical properties Geometric Isomers: Same molecular formula but are arranged differently in space; this happens when rotation is restricted by a double bond. Optical Isomers: All compounds that contain at least one asymmetric or chiral carbon atom within the molecule. They have identical physical properties and differentiate the way they rotate plane-polarized light.

8.) Oy vey! More structures, sorry!!!!!

9.) Because they rotate plane-polarized light.

10.) Enantiomers: non-super imposable mirror image isomers Chiral: Describes an asymmetric molecule. A chiral carbon is the carbon that has 4 different things attached to it. Achiral: Describes a symmetric molecule. Optical Isomers: All compounds that contain at least one asymmetric or chiral carbon atom within the molecule. They have identical physical properties and differentiate the way they rotate plane-polarized light. Polarized light: light waves that vibrate in one plane Polarimeter: instrument used to measure the angle that the light is rotated

11.) Most of these are relative statements, but I promise I 2x checked w/Nagel on their validity.

Short chains, branched/spherical molecules, and alkanes are more volatile than alcohols, amines, and amides

Alkanes are not water solubleHexanol is slightly solubleLong chain alcohols, aldehydes, acids, and amides are not soluble

Carboxylic Acids (Surprise!!!) , Aldehydes, and Ketones are acidic

Amides & Amines are basic

Alcohols can be either slightly basic or slightly acidic depending on situation.

Pages in Green Book:

62-66, 68, 72, and 73

Good luck!!!! I know you will all do magnificently on this test tomorrow!!!!!

Appendix: General Formulas and Autumnah’s Mnemonics

A1. Formulas for Homologous structures:

Alkanes: CnH2n+2

Alkenes: CnH2n

Alkynes: CnHn

A2. Formulas for Functional Groups:

(Alkanes, Alkenes, and Alkynes: R)

Halides: R-X (where X is F, Cl, I, or Br)Alcohols: R-OHAldehydes: R-HOCarboxylic acids: RCOOH

(ie RC=O | H)

Ketones: R-C-R | O(this is a carbonyl group, R-C-O, but with the O in the middle of

stuff)

Ethers: R-O-R’Esters (more commonly shown): R-C=O

| O-R’

(BE SURE TO NAME R’ FIRST with esters!! Eg PHSIBOATE, not IBPHSOATE—the poster is named backwards)

Amine: RNH2

Amide: R-C=O | NH2

A3. Mnemonics (mnemone-ics)Remember Amines vs. Amides:

AmiDes have a Double-bond-O in aDDition to NH2

AmiNes have Nothing but NH2

A4. Generally important things to remember:Always go alphabetically in naming entire molecules—but prefixes (eg dimethyl) DON’T COUNT! So it’s 2,3-ethyl-4-dimethlyheptane—dimethyl does not come first)

A5. If it helps you, look for and circle the parent chain first (be sure to look for all the twists and turns for the longest one), and name that as a base. THEN go looking for branches and functional groups, and name those.

Finally, get whatever good night’s sleep/restful studying you can.Good luck!