Organic Chemistry - Chem Honors

Organic vs. inorganic

• organic chemistry is the study of carbon containing compounds

  • Ex. fuels, plastics, alcohols, fats, proteins, ethers, sugars, aldehydes

• look for carbon in molecular formulas

• exceptions are CO, CO₂, and carbonates (XCO₃) - all inorganic

Properties of inorganic

• ionic bonds with crystal lattice

• polar compounds

• strong IMFs

• fast rate of reaction

• high melting and boiling point

• solids at STP

• low vapor pressure

Properties of organic

• covalent bonds with molecules

• nonpolar molecules

• weak IMFs

• slow rate of reaction

• low melting and boiling point

• gases (some liquids) at STP

• high vapor pressure

Structure

• carbon has 4 valence electrons so it forms 4 covalent bonds

• can bond to itself and many other elements

• can have single, double, or triple bonds

• SP hybridization so the 4 electrons act the same in one orbital create not normal looking lewis dot

• carbon can form long, repetitive chains called polymers

• unusual length and elasticity of polymers due to great length and high molecular weight

What’s made of carbon?

• living things (cellulose, DNA)

• fuels (fossil, bio)

• paints, coatings, and adhesives

• industrial applications (bakelite)

• plastics (name anything and it’s most likely plastic)

• synthetic fibers (nylon)

Hydrocarbons

• molecules that only contain carbon and hydrogen in their formulas

• can have single, double, or triple bonds (Table Q)

  • alkanes have single bonds

  • alkenes have at least one double bond

  • alkynes have at least one triple bond

• saturated hydrocarbon means it contains max number of hydrogen atoms possible

  • alkanes are saturated

• basic naming

  • prefix (number of electrons)

  • suffix (type of bonds)

  • use Table P and Q

Simple hydrocarbons

• butane - C₄H₁₀

• ethene - C₂H₄

• propyne - C₃H₄

• pentene - C₅H₁₀

• hexyne - C₆H₁₀

• propane - C₃H₈

Isomers

• same molecular formula but different structural formula

  • Ex. straight chain butane - C₄H₁₀

    • has bp. 0.5 degrees Celsius

    • branched chain methyl propane - C₄H₁₀

    • has bp. 10 degrees Celsius

Naming hydrocarbons (IUPAC)

• Last name

  • 1. find # of carbons in parent chain/longest continuous group of carbons

    • # of C = prefix from Table P

  • 2. find single, double, or triple bonds

    • bond type = suffix from Table Q

  • 3. note location of any multiple bonds

    • label numbers in direction that puts lowest number on the carbon with multiple bonds

    • use di- or tri- if there’s more than one multiple bond

    • this # is listed before the last name (2 in 2-Pentene)

• Ex.

Naming hydrocarbons (IUPAC)

• first name

  • 1. name side chains branching off of parent chain

    • count # of C in side chain

    • name - prefix from Table P + “yl” (1 carbon = methyl)

    • side chains are listed in alphabetical order (ethyl before methyl)

    • use di- or tri- as needed

  • 2. note location of side chains branching off of parent chain

    • label numbers in direction so branches get lowest number

      • if C already numbered due to having multiple bonds, use that numbering (if you have double or triple bonds within parent chain)

      • # is listed before first name (4 in 4-methyl)

• Ex.

  • whole name becomes 4-methyl-2-pentene

Branched hydrocarbons

• Ex. 2, 2, 4 trimethyl pentane

• Ex. 2, 3-dimethyl hexane

• Ex. 2, 4-dimethyl-1, 3-pentadiene

Cyclic hydrocarbons

• all have single bonds

• Ex. cyclopropane - triangle

• Ex. cyclobutane - square

• Ex. cyclopentane - pentagon

• Ex. cyclohexane - hexagon

Aromatics

• cyclic hydrocarbons with double bonds

• electrons shared evenly around the ring

• structure means very different properties compared to other compounds

• fragrant - cloves, vanilla, almond essence

• each carbon equally sharing electrons and experiences “resonance”

Functional groups

• specific groups of atoms or bonds within molecules that are responsible for the characteristic chemical properties and reactions of those molecules

• create polar molecules which dissolved in water

  • alcohols are soluble in water

• Table R

Halides

• Ex. 1,1 dibromopentane

Alcohols

• Ex. 2-butaonol (secondary alcohol bc OH^- is on 2nd carbon)

Ethers

• Ex. Methyl propyl ether (shorter group first)

Aldehydes

• Ex. Butanal (double bond O and H always at first or last carbon)

Ketones

• Ex. 2-butanone

Organic acids

• Ex. Pentaonic acid (always at first or last carbon)

Esters

• Ex. Ethyl butanoate (one on oxygen goes first)

Amines

• Ex. Ethanamine

Amides

• Ex. Heptanamide

Reactions

• addition

  • always unsaturated hydrocarbon (double or triple bonds)

  • break a multiple bond and add in two new atoms

  • Ex. C

• substitution

  • always saturated hydrocarbon (single bonds)

  • single replacement of one hydrogen with another atom

  • Ex. C₂H₄ +Br₂ → C₂H₄Br₂

• combustion

  • oxidation of a hydrocarbon

  • needs O₂

  • Ex. CH₄ +2O₂ → CO₂ +2H₂O

• fermentation

  • sugar reacts with an enzyme as a catalyst (zymase) to make alcohol and CO₂

  • Ex. C₆H₁₂O₆ → CO₂ + 2C₂H₅OH

• esterification

  • organic acid and alcohol makes an ester and water

  • Ex. CH₃COOH + C₂H₅OH → C₄H₈O₂ + H₂O

• saponification

  • hydrolysis of fats by bases create an alcohol and soap

  • soap has polar and nonpolar end

  • Ex. C₂₁H₉₉O₆ + 3NaOH → C₃H₉O₃ + 3C₁₆H₃₁O₂Na

• polymerization

  • monomers join to make polymers (repeating units)

  • usually joining unsaturated molecules

Polymers

• natural and synthetic

• types of polymers are linear, branched, cross-linked, network

• linear held by London Dispersion forces

• branched more flexible and less dense because of random branches

• cross linked help by covalent bonds

• thermosetting - once it’s set/cooled, shape won’t change

• network has lots of crosslinks making it tight and not flexible

Condensation polymerization

• two monomers join to make a big molecules and water

• usually joining saturated molecules