T 10 - Organic Chemistry Flashcards
How many bonds does the following atom have in an organic compound?
Carbon
4 bonds
How many bonds does the following atom have in an organic compound?
Oxygen
2 bonds
How many bonds does the following atom have in an organic compound?
Nitrogen
3 bonds
How many bonds does the following atom have in an organic compound?
Hydrogen & Halogens
1 bond
Synonym to “carbon chains”
Hydrocarbon skeletons
The (atom(s)/particle(s)?) that gives an organic compound its properties
Functional group(s)
Functional group of Alkanes
+ name of functional group
None!
Functional group of Alkenes
+ name of functional group
Double bond
+ Alkenyl group
Functional group of Alkynes
+ name of functional group
Triple bond
+ Alkynyl group
Functional group of Arenes
+ name of functional group
Delocalized electrons in a ring system
+ Phenyl group
Functional group of Alcohols
+ name of functional group
R-OH
+ Hydroxyl group
Functional group of Ethers
+ name of functional group
R-O-R’
+ Ether group
Functional group of Aldehydes
+ name of functional group
RCHO
+ Aldehyde (group?)
Functional group of Ketones
+ name of functional group
R-CO-R’
+ Carbonyl group
Functional group of Carboxylic Acids
+ name of functional group
R-COOH
+ Carboxyl group
Functional group of Esters
+ name of functional group
R-COO-R’
+ Ester group
Functional group of Amides
+ name of functional group
e.g. RCONH2
+ Carboxy amide group
Functional group of Amines
+ name of functional group
e.g. R-NH2
+ Amino group (amine group)
Functional group of Nitriles
+ name of functional group
R-CN (triple bond CN)
+ Nitrile group
Primary amine (structure)
R-NH2
Secondary amine (structure)
R-NH-R(‘?)
Tertiary amine (structure)
R-N-2R (bonds to three C or R)
Define a Homologous Series
[Series of molecules that] only differ by [the presence of] 1 extra C and its 2 H atoms. They have the same functional group and belong to the same family (class?)
Properties in a homologous series
Chemical properties remain ~ same
Physical properties gradually change as the carbon chain gets longer
How does boiling point change in a homologous series?
Refer to (alkanes/alkenes?) and alcohols
(Alkanes/alkenes I think) gradual increase going down the series; as the molar mass incr., so do the London forces — more E required
Alcohols also gradual increase (same reason^^), but start higher due to hydrogen bonds
Equation for the n of C & H in
Alkanes
Alkenes
Alkynes
Alkanes CnH2n+2
Alkenes CnH2n
Alkynes CnH2n-2
Equation for the n of C & H in
Alcohols
Carboxylic acids
Alcohols CnH(2n+2)O (alkane + O)
Carboxylic acids CnH2nO2 (aldehyde + O)
Equation for the n of C & H in
Aldehydes
Ketones
Aldehydes & Ketones CnH2nO (both same!)
A structural formula provides info of…
… HOW the atoms are bonded together
Non-cyclic alkanes
not in a ring (think “normal”)
Isomers =
= same molecular formula (consisting particles), but different structures
How do you name Alkanes?
- Longest carbon chain - end of name
- Number carbons so those w substituents have lowest possible
- Name substituents + alphabetize
What are these substituents called?
Cl, F, Br, I
Chloro, Fluoro, Bromo, Iodo
What are these substituents called?
CH3, C2H5, C3H7, …
Methyl, Ethyl, Propyl, …
How do you name Alkenes?
- Longest carbon chain that INCLUDES double bond - use name + -ene
- Number carbons so those WITH double bond have lowest possible number
- Name substituents + alphabetize
How do you name Alkynes?
- Longest carbon chain that INCLUDES triple bond - use name + -yne
- Number carbons so those WITH triple bond have lowest possible number
- Name substituents + alphabetize
Functional group of +
How do you name
ALCOHOLS?
R-OH
usual + ending -ol
Functional group of +
How do you name
ALDEHYDES?
R-CHO
usual (-number always 1) + ending -al
Functional group of +
How do you name
KETONES?
R-CO-R’
usual + ending -one
Functional group of +
How do you name
CARBOXYLIC ACIDS?
R-COOH
usual (-number, always 1) + ending -oic acid
Functional group of +
How do you name
HALOGENOALKANES?
R-X
the halogen is a substituent
Functional group of +
How do you name
ARENES?
Benzene ring
substituents + benzene
What is benzene called when it is a substituent?
= phenyl
Functional group of +
How do you name
ESTERS?
R-COO-R’
split between the O-R’
R-COO = alkane name + -oate
-R’ = alkyl group (methyl, ethyl, propyl etc)
put together = **yl **oate
Functional group of +
How do you name
AMINES?
Primary & not
R-NH2 (ex?)
Primary: use as substituent e.g. Amino ethane, 2-amino propane
Not primary: use -amine and substiuents e.g. dimethyl amine, ethyl-methyl amine
Functional group of +
How do you name
AMIDES?
R-CONH2
ending: -amide
Functional group of +
How do you name
NITRILES?
R-CN
ending: -nitrile
e.g. Propanenitrile
What is a PRIMARY carbon?
& Its notation?
C atom only bonds to ONE other C atom
1°
What is a SECONDARY carbon?
& Its notation?
C atom bonds to TWO other C atoms
2°
What is a TERTIARY carbon?
& Its notation?
C atom bonds to THREE other C atoms
3°
Define volatility
+ what is considered volatile?
How easily it forms gas/Ease to evaporate at room T
Low boiling point (<100°C) considered volatile
What does the boiling point depend on?
length of carbon chain — incr. M — stronger London Forces
Is a straight or branched chain/compound more volatile?
+ why?
Branched!
Straight - closer – larger surface A in contact —- stronger L.F.
Branched - molecules further apart – smaller surface A in contact —- weaker L.F. — more volatile
Are aldehydes, ketones and halogeoalkanes volitile? Explain + how it changes
w. short C-chains (low boiling point) volatile
as length incr. — less volatile (decr)
Volatility of halogenoalkanes
rather high molecular masses — reasonably high b.p. (low volatility)
but the smallest still considered volatile
Volatility alcohols, carboxylic acids
Alcohols and carboxylic acids have hydrogen bonds that are stronger than dipole-dipole
and London forces. Methanol and Ethanol have boiling points below 100 °C and are
therefore considered volatile.
Volatility aldehydes, ketones, halogenoalkanes
Aldehydes, ketones and halogenoalkanes have dipole-dipole and London forces.
Aldehydes and ketones with short carbon chains have low boiling points and are
volatile, but as the carbon chain length increase the volatility decreases.
An organic compounds solubility in water depends on…
… the polarity of the functional grp (+n of them) & the chain length
Is a longer carbon chain more or less likely to dissolve in water?
Less!
longer C-chain — less likely to dissolve in water
Solubility alcohols, aldehydes, ketones and carboxylic acids in water? + how it changes
alcohols, aldehydes, ketones and carboxylic acids w. short carbon chains easily soluble.
As length incr. — sol. decr.
The n of funct.grps also influences sol.
What is the physical evidence for the structure of benzene? (3 points)
- Same bond lengths
- The C-C-C bond angles are all the same
- The molecule is planar (flat)
What is the chemical evidence for the structure of benzene? (3 points)
- The enthalpy of hydrogenation of benzene is lower than expected.
- There is only one isomer of 1,2-dihalogenobenzene (if double bonds there would be 2)
- If it had double bonds it would react in addition reactions, but it doesn’t; instead it undergoes Substitution reactions.
Are alkanes reactive or not? + why
Alkanes are quite unreactive (inert), due to the rel. strong C-C and C-H bonds and bc of the low polarity of these bonds
What are the main reactions of alkanes?
- Combustion w. oxygen
- Substitution reactions w. halogens in UV-light
Explain the combustion w oxygen (alkanes)
alkanes burn in oxygen/air →CO2 + H2O
highly exothermic (bonds prod much stronger than react.) (used as fuels)
Not always complete combustion. If not enough O2 → CO (toxic) + somet. C (inhale danger.)
Sometimes doesn’t burn
Also env problem as → CO2 → global warming
Explain the substitution reaction w. halogens (for alkanes). + what does it require?
Alkane + halogen (X2) → halogenoalkane + HX
Requires UV-light
Mechanism chlorination of methane
What does volatility relate/refer to?
A substance’s ease of evaporating at room temperature.