Chapter 1

Question 1

In science, the term organic means

Answer 1

anything that is or has been alive

Question 2

Organic chemistry is

Answer 2

a branch of chemistry which involves the study of the chemical compounds consisting primarily of carbon and hydrogen

Question 3

The key to they variety of organic compounds that exist lies in the unique bonding abilities of the carbon atom, which are…

Answer 3

1) Carbon atoms can form strong single, double, & triple bonds in various length –> with other atoms like oxygen & nitrogen, you can’t make large molecules cuz then they become unstable. Ex. 3 oxygen=ozone

2) Carbon atoms can form linear or branched molecules

3) Carbon atoms may be arranged in rings to form a variety of structures with different shapes –> u can have multiple rings attached to each other as well

4) Carbons can form very large and complex compounds

Question 4

Why can’t Oxygen or Nitrogen form compounds like carbon?

Answer 4

-with oxygen & nitrogen, you can only make 1 double or triple bond and ur done
- u can’t make a lengthy, large molecule –> bigger molecules of Oxygen & Nitrogen are also unstable
–> Ex, 3 oxygen=ozone

Question 5

Lewis Structure

Answer 5

only show the valence electrons

Question 6

Nomenclature rules for ALKANES

Answer 6

1) The parent must be the longest C-C chain, C1 must be closest to the branches

2) The branches must be listed in alphabetical order, with the SMALLEST POSSIBLE # for the branches

3) When the branches are identical, use the prefix “di, tri, tetra…” to indicate duplicity

4) Between 2 # there must be a comma

5) Between a # and a letter, there must be a dash (-)

-rmr when determining alphabetical order, don’t include prefix
- carbon #1 is end closest to the branch
- if branches are at same distances no matter where you start, C gets greater priority over halogen
- rmr we want the smallest branch #s

Question 7

Name of Branches

Answer 7

-Br= bromo
-Cl= chloro
-F= fluoro
-I= iodo
-OH= hydroxy
-NH2= amino
-NO2= nitro

Question 8

Nomenclature rules for ALKENES

Answer 8

there must be at least one double CC bond

• The parent must contain the double bond(s), even if it’s not the longest possible chain
• C1 must be closer to the double bond, even if C1 is further from the branches
• In a ring, the CC double bond must be the first bond. It’s location can be skipped if there’s only 1 double bond

-if there is a branch on one end of the double bond, make that branch #1
- between the hept - 2 - ene, u can’t have a –1) consonant, consonant 2) vowel, vowel

Question 9

ALKYNE

Answer 9

there must be at least 1 CC triple bond

Question 10

Isomers are

Answer 10

molecules that have the same molecular formula but their atoms are in different arrangements

Question 11

Constitutional Isomers

Answer 11

• molecules that have the same molecular formula, but different atom-to-atom connection
  -Example: A-B-C, A-C-B, B-A-C

rmr Linear Alkane formula = CnH2n+2
- Double bond: lose 2H
- Ring: lose 2H
- Triple bond: lose 4H

Question 12

Stereoisomers

Answer 12

• molecules that have the same molecular formula and atom-to-atom connection but differ in 3D orientations of their in space
• Cis-isomer: larger groups are on the same sides of the double bond
• Trans-isomer: larger groups are one the opposite sides of the double bond

Question 13

Aromatics

Answer 13

• special group of cyclic hydrocarbons. They appear to have alternating single & double bonds
• The electrons are equally shared around the ring - there are no single or double bonds in benzene. Instead, we have 6 identical 1.5 bonds (halfway between single & double bonds)

Nomenclature
The benzene is the parent unless:
- the linear chain contains a double bond, a triple bond or have more than 6 carbons, then the linear chain is the parent & the benzene ring is a branch called “phenyl”

Question 13

Combustion Reactions

Answer 13

• All hydrocarbons burn rapidly with O2 to produce CO2, H2O, & a large amount of energy (heat & light)
• These reactions are not spontaneous & must be started by a spark, heat or light
• Combustion of fossil fuels is a major source of useful energy for humans. –> Ex, natural gas, gasoline, kerosene, candles, wax, jet fuel

Question 13

Complete Combustion Reactions

Answer 13

Occurs when the oxygen supply is unlimited (excess reagent)
- Products: CO2 + H2O+ lots of energy
- Ideal way to burn fuel cuz it releases the most energy from the fuel molecules
- Produces the cleanest & hottest flames (blue)

Question 14

Incomplete Combustion Reactions

Answer 14

Occurs when oxygen supply is limited (limiting reagent) –> like in an enclosed space
- Products: CO2, H2O, CO, C, & less energy
- Flames are often sooty (like the black fume that comes out of cars), yellow, & cooler
- excess CO can cause headaches & breathing difficulty –> CO binds to hemoglobin in out blood & does not allow blood to carry O2 as easily. –> increased levels of CO in blood can cause death

Question 15

Why don’t we cook with gasoline (C8H18)

Answer 15

1) bad smell
2) u would need a lot of oxygen for a complete combustion reaction

Question 16

Addition Reaction of Alkenes

Answer 16

• hydrocarbons that contain only single CC bonds (alkanes) are called SATURATED and are not very reactive
• UNSATURATED hydrocarbons contain double & triple bonds & r much more reactive
• Alkenes & alkynes undergo addition reactions in which atoms are added to a double or triple bond. End product=alkanes

Question 17

Addition Reaction of Alkenes: Markovnikov’s Rule

Answer 17

For addition of HX to alkenes, the H atom adds to the Carbon with the most atoms to give the major product
- treat H like money –> THE RICH GETS RICHER

Question 18

Elimination Reactions

Answer 18

• opposite of addition reaction –> H & X are removed to form a double bond between 2 carbon atoms
  alkane –> alkene
• first identify the x
• then find the hydrogen u can remove. HAS TO BE 2 CARBONS AWAY
  For our purposes, it produces constitutional isomers

Question 19

Hydrocarbons: gas to solid

Answer 19

Alkanes with 1-4 carbons=gas=cooking & heating
Alkanes with 5-16 carbons=liquids=run devices with engines
Alkanes with 16-22 carbons=heavy liquids=lubricating oils
Alkanes with >18 carbons=semi-solids= candles, waxed paper, & cosmetics
Alkanes with >26 carbons=solid residues= asphalt & tars 4 roofing & paving

Question 20

Physical Properties are

Answer 20

properties that can be observed without changing the composition of the matter

Question 21

Intermolecular forces are

Answer 21

attractive forces between molecules and largely determine the physical properties of a compound
- DO NOT SAY INTERMOLECULAR BONDS

Question 22

Attractive (intermolecular) forces between hydrocarbon molecules are called

Answer 22

london dispersion forces
- DO NOT SAY BONDS

Question 23

The strength of the London Dispersion Forces depends on......

Answer 23

the amount of surface contact between molecules Larger size of molecule=greater surface area=stronger LDF=requires more energy to break=higher melting & boiling points

Question 24

Physical properties of Hydrocarbons: Physical state

Answer 24

Large hydrocarbon molecules are more attracted (closer) to each other & they tend to be solids, while smaller ones are liquid or gases due to weaker intermolecular forces

Question 25

Physical properties of Hydrocarbons: Melting & Boiling Points

Answer 25

as the hydrocarbon gets larger, the attraction between molecules becomes stronger. More energy is needed to separate the molecules. As a result, the boiling points increase - rmr room temp = 25 degrees celcius

Question 26

Physical properties of Hydrocarbons: Solubility

Answer 26

hydrocarbons have very low solubility in H2O cuz they are non-polar

Question 27

Distillation is

Answer 27

a process used to separate the various hydrocarbons in a mixture from one another by using differences in boiling points

Question 28

How does Fractional Distillation work?

Answer 28

1) Mixture is heated @ high temp= ensures all all alcohol evaporate. Gases will condense @ diff temps (their boiling points) 2) Methanol=lowest boiling point, will evaporate 1st. As methanol travels down a fractionating column that has a large surface on which it can condense into a liquid & is collected as a condensate or distillate. 3) Once methanol has been boiled off, ethanol will be next to evaporate. This is repeated till all alcohols are boiled off & collected. Impurities that were dissolved in H2O will remain as RESIDUE in original flask REFLUX= substances with lower boiling points travel further up the column. At the same time, others with higher boiling points drip back down - the component liquids thus proceed at diff rates up the fractionating column so as u move up, the mixture becomes increasingly richer in the liquid with the lower boiling point - If the substance in the mixture have boiling points that are far apart, & the fractionating column is long enough, eventually the liquid components separate completely after the other.

Question 29

Fractional Distillation in Crude Oil ( substances that travel highest to lowest)

Answer 29

1) gases= C1-4=propane 2) Naphtha=C5-9= chemicals 3) Kerosene=C5-10 4) Diesel oil=C10-16=kerosine (paraffin oil) 5) Lubricating oil= C14-20= Diesel oils 6)fuel oil=C20-70 7) residue=>70

Question 30

The most valuable hydrocarbons in petroleum aka crude oil are

Answer 30

C5-12 cuz they are the components of gasoline

Question 31

Engine Knocking

Answer 31

AKA pinging or detonation, occurs when the air-fuel mixture in the combustion chamber ignites prematurely or unevenly. Instead of the fuel burning in a controlled, smooth manner after being ignited by the spark plug, pockets of the mixture explode before the spark or at the wrong time. This causes a knocking or pinging noise in the engine

Question 32

Cracking

Answer 32

It's a process used to break down large hydrocarbon molecules into smaller, more desirable ones like high-octane gasoline - the hydrocarbon chains are heated to a high temp of about 400-500 alongside a catalyst. - This heating reaction, sped up by the catalyst, breaks the chains down - it's an important process cuz it increases the yield of desired products from the same amount - cracking is also used to break apart larger hydrocarbons like kerosene into smaller ones like ethane & propene (used in plastic production)

Question 33

CH ratio formulas

Answer 33

alkanes: CnH2n+2 alkene with 1 double bond: CnH2n alkyne with 1 triple bond: CnH2n-2 cyclo alkane: CnH2n