CHEM 1C EXAM 2

Chapters 19, 21, 20.1-20.4

Alkane

• find longest carbon chain (may not be straight)

• "end with ‘ane’, in between branches end in “yl” and halogens end with ‘o” with the corresponding carbon #

• saturated hydrocarbon

  - no multiple(double/ triple)bonds

  - holds max amount of hydrogens

• unsaturated hydrocarbon

  -has multiple bonds

Benzene Ring

• aromatic compounds

• delocalized pi bonding

• contains alternating double bond

• name halogen branches alphabetically

Alcohol

• bent shaped

• sp2 hybridized

• IMFS: LDF, D/D, H-Bond

• polar, soluble in H2O

• can lose OH- or H+ (amphoteric)

• remove suffix “-e” from the parent alkane chain name and add the suffix “-ol”

Ether

• bent («109.5°)

• small ethers are polar

• name shorter part, branch with oxygen, end in “oxy”

• longest carbon branch ends in “ane”

Aldehyde

• drop “-e “ from alkane name and add ending “-al”

• small aldehydes are polar

• IMF: LDF, D/D

• sp2, trig planar

• 120°

ketone

• drop “-e “ from alkane name and replace end with “-one”

Carboxylic Acid

• amphoteric

• soluble in H2O

• higher BP

• The suffix of this carbon chain is then replaced, as carboxylic acids always end in "-oic acid."

Ester

• first count carbon chain in R’, end in ”-yl”

• second count carbons in R, end in “-oate”

Amides

• contain N and carbon chain

• primary, secondary and tertiary

Alkyne

• triple bonded alkane

• name where triple bonds are located

Alkene

• double bonded alkane

• name where double bonds are located

Other Alkane Groups

• “iso” represents Y shaped branching

• other examples: sec-butyl, tert-butyl

How to count carbons?

• start counting from the end of the chain closest to the nearest components (‘yl’ groups)

• Multiple “‘yl’ groups” are named individually and placed in alphabetical order at the front of the name.

Multiple of the same branches while naming alkane?

• add “di, tri, tetra, penta, hexa, hepta…” prefix

Halohydrocarbon

• contains halogens

• multiple halogens are named in alphabetical order

Isomers

same # and type of atom

• different bonds

• different formula

• different name

Stereoisomers

• same bonds, different orientations

• same formula

• different names

  ex: cis/trans, optical isomers

Crystal Field Theory

deals with d-orbital orientations and covalent bonds to transition metals

• eg on axis (electron density)

• t2g between axes

Splitting Energy

computing 2 different affects

1. energy from pairing

2. energy from promotion

when Δ = small, e⁻ would rather be promoted *high spin

when Δ = large, e⁻ would rather be paired *low spin

Spectrochemical Series

ligands tell us if octahedral is strong or weak field if not specified

given to us :)

How do we see color?

• result in e⁻ transition between eg —> t2g

• e⁻ can absorb photon for promotion

  -absorbed light depends on splitting energy, we see reflected light, which are opposite sides of color wheel

Cis Isomers

same elements are next to each other

Trans Isomers

same elements are across from each other

Optical Isomers

• one molecule is mirror image

• cannot superimpose (wont fit together)

  ex: tetrahedral

octahedral d-orbital diagram

look at spectrochemical series. Series goes from weakest field to strongest field.

tetrahedral d-orbital diagram

Δ=small, weak field so e⁻ would rather be promoted

square planar d-orbital diagram

Δ=large, strong field so e⁻ would rather be paired