S1-L11: Introduction to Organic Chemistry Flashcards
What is key about carbons valency when drawing molecules? (figure 1)
- Carbon has valency of 4
- ->so forms 4 bonds with other atoms
Outline the following classifications of carbon:
1-Primary
2-Secondary
3-Tertiary
4-Quarternary
1-C atom bonded to one other C atom (or heteroatom)
2-C atom bonded to 2 other C atoms
3-C atom bonded to 3 other C atoms
4-C atom bonded to 5 other C atoms
Define a hydrocarbon
-molecules containing only C and H atoms
What are saturated and unsaturated hydrocarbons?
- saturated have only one single C-C bonds- alkanes
- unsaturated contain C=C bonds- alkenes/ aromatics/ alkynes
Describe alkanes including their general formual
- contain max possible n. of H atoms per C atom
- all C-C bonds single covalent bonds
- linear molecules
- general formula: CnH2n+2
- ->such as hexane (C6H14)
Outline and describe cycloalkanes
- cyclic molecules with general formula CnH2n
- ->like cyclohexane
- n: positive whole number for all hydrocarbons
What are Alkenes AND alkynes?
- unsaturated molecules
- contain minimum 1 double OR triple bonds-respectively
- fewer H atoms per carbon than alkanes
Outline and state the general formula for each of the following:
1-Mono-Alkenes
2-Mono-Alkynes
3-Aromatics
1-contain C=C bond
–>general formula is CnH2n (figure 2)
2-contain C triple bond
–>general formula is CnH2n-2 (figure 3)
3-usually one or more rings of 6 C atoms called benzene rings (figure 4)
What are the 5 main types classifications of organic compounds based on C chains/ rings OR functional groups?
- aliphatic (alicyclic)
- ->saturated AND unsaturated (alicyclic)
- ->alicyclic (cyclic)
- aromatic (cyclic)
- heterocyclic (cyclic)
Define an aliphatic compound
-compound containing open chain of C atoms OR non-aromatic compounds
Give examples of saturated and unsaturated compounds
- saturated: ethane (CH3CH3)/ ethyl alcohol (CH3CH2OH)
- unsaturated: ethene (CH2=CH2)/ Ethyne (CH—CH) triple bond (unsaturated)
Define the following types of organic compounds:
1-Alicylcic
2-Atomatic
3-Heterocyclic
1-compounds containing non-aromatic rings of C atoms (figure 5)
2-contain ring where all atoms unsaturated (and conjugated)- figure 6
3-contain ring made up of C AND at least one other element like N/S OR O (figure 7)
Explain what functional groups in molecules are (refer to figure 8)
- gives its characteristic chemical properties
- acts as chemical activity site
- serves as basis for nomenclature
- ->classifies its family
For each of the following compounds outline:
Compound–>general structure–>example–>F. Groups
1-Alkyl Halide 2-Alcohol 3-Ether 4-Amine 5-Thiol 6-Sulfide 7-Aldehyde 8-Ketone 9-Carboxylic Acid 10-Ester 11-Amide 12-Acid Chloride
(refer to figure 9 for a visual on general structures)
1-Alkyl Halide–>R-X (X=F/Cl/Br/I)–>CH3Br (methyl bromide)–>X halo
2-Alcohol–>R-OH/ CH3-OH (methanol)/ -OH (hydroxy)
3-Ether–> R-O-R/ H3C-O-CH3 (dimethyl ether)/ -OR (alkoxy)
4-Amine–>R-NH2/R2NH/R3N/CH3-NH2 (methylamine)/N(R/H)(RH)/(R) Amino
5-Thiol–> R-SH/ CH3-SH (methanethiol)/ -SH (Thio/Mercapto)
6-Sulfide–>R-S-R/ H3C-S-CH3 Methylthiomethane (dimethylsulfide)/ -SR (Alkathio)
7-Aldehyde–>(R)C=O(H)/ CH3CHO (Ethanal)/ -CHO (carbonyl)
8-Ketone–>(R)C=O(R)/CH3COCH3 propane (acetone)/ C=O carbonyl
9-Carboxylic Acid–> (R)C=O(OH)/ H3CCOOH Ethanoic (acetic) Acid/ -CO2H Carboxyl
10-Ester–> (R)C=O(OR)/ H3CCOOEt Ethyl acetate/ -CO2R (R=alkyl)
11-Amide–> (R)C=O(NR/H2)/ H3CCONH2 Acetmaide/ -CO2NR2 (R=H OR alkyl)
12-Acid Chloride–>(R)C=O(Cl)/ H3COCl Ethanoyl (acetyle) chloride/ -COCl
What are polyfunctional compounds?
- contain more than 1 functional group
- principle functional groups
- secondary functional groups treated as substituents
Outline the order of preference for principle group
-Carboxylic Acid> esters> acid halides> amides> nitriles> aldehydes> ketone> alcohols> amines> double bond> triple bond> halogen> nitro
What is a Homologous Series?
- group of organic compounds with similar chemical properties in which members contain same functional group
- ->but differ by C chain length-adjacent members differ by CH2 unit
Outline the features of successive members of homologous series (homologues)
- same general formula
- prepared by similar methods
- gradual variation in physical properties with increasing molecular weight
Homologous series examples:
Outline the first 4 for each
1-Alkane
2-Alcohol
3-Aldehyde
4-Carboxylic Acid
1-Methane (CH4), Ethane (CH3CH3), Propane (CH3CH2CH3), Butane (CH3CH2CH2CH3)
2-Methanol (CH3OH), Ethanol (CH3CH2OH), CH3CH2CH2OH (Propan-1-ol), CH3CH2CH2CH2OH (Butan-1-ol)
3-Methanal (HCHO), Ethanal (CH3CHO), Propanal (CH3CH2CHO), Butanal (CH3CH2CH2CHO)
4-Methanoic (HCOOH), Ethanoic (CH3COOH), Propanoic acid (CH3CH2COOH), Butanoic acid (CH3CH2CH2COOH)
How are straight chain alkanes named?
- named with base depending on n. of atoms in C chain AND suffix -ane
- figure 11 outlines first 7 alkanes
Outline the steps which must be followed to name molecules
1-find AND name longest continuous C chain
–>this is parent chain- such as methane/ propane etc
2-number chain consecutively starting at end nearest attached group-substituent
3-identify & name groups attached to this chain
–>example: methyl-/ bromo- etc
4-designate location of each substituent with n. of the C parent chain on which group attached
–>place dashed line between numbers AND letters (e.g: 3-chloropentane)
5-assemble name- listing groups in alphabetical order
6-prefixes di-/ tri-/ tetra- etc used to designate several groups of same kind not considered when alphabetising
–>place comma between multiple numbers (e.g: 2,3-dichloropropane)
Naming molecules other than alkane:
1-Identifying and naming functional group(s)
1-replace -ane with identified for principle functional group
–>if required location of principle functional group identified between dashes before before its name like hex-2-ene
2-Finding carbon chain/ring (refer to figure 12)
2-number parent chain OR ring so attached groups on lowest numbers
3-Naming attached groups
- hydrocarbon (alkyl) groups:
- ->methyl (-CH3 Me)/ Ethyl (CH3CH2-Et)/ Propyl (CH3CH2CH2- Pr)
- Halogens:
- ->fluoro (F-)/ Chloro (Cl-)/ Bromo (Br-)/ Iod (I-)
4- Designating and naming groups (refer to figure 13)
4-use number of parent chain from step 2 to designate location of attached groups to parent chain
- prefixes di-/ tri-/ tetra- etc used to designate several groups of same kind
- prefixes not considered when assigning alphabetical order
- ->like dimethyl= m
- parent chain goes last
How may structural isomers of organic compounds be distinguished?
-can be distinguished by prefixes indicating type of branching present in C chain
What do the following prefixes indicate about the type of alkane?:
1-n
2-iso
3-neo
(refer to figure 14)
1-alkane unbranched
2-alknae contains (CH3)2CH- AND not other branches
3-alkane contains (CH3)3C- AND no other branches