TOPIC 18 - Organic chemistry III Flashcards
What happens to the 4 valent electrons in the carbon atoms in benzene?
- 2 of them are in two C-C bond.
- 1 is bonded to H
- 1 p-orbital electron is part of the delocalised ring of electron.
What is the length of the C-C double bond? Why?
139 pm.
It is between length of single C-C bond (154pm) and the length of double C=C (134pm) because the delocalised ring of electron increases the strength of the C-C bond slightly, without reaching the strength of the C=C.
Why do we know that benzene is more stable than cyclohexa-1,3,5-ene?
- Enthalpy of hydrogenation of cylohexene (1 C=C) = -120kJ/mol.
- Expected enthalpy of hydrogenation of benzene = enthalpy hydrogenation of cyclohexa-1,3,5-ene.
- Actual experimental value: -208kJ/mol.
- So more energy is required to break the bonds in benzene than in cyclohexa-1,3,5-ene. Therefore benzene is more stable.
What is the main reason why benzene is so stable?
The delocalised ring of electrons.
What is the equation for the complete combustion of benzene?
Does benzene usually burn completely?
No. A lot of soot is produced and a black smoky flame is observed.
Does benzene undergo electrophilic addition reactions easily? (like the bromination of alkenes)
Why?
What recations to they undego instead?
No. Benzene is stable and so doesn’t undergo these types of reaction since it would sirupt the stable ring of electrons.
Instead, they undergo electrophilic substitution, where a hydroger or functional group is substituted by the electrophile.
What are aromatic compounds (arenes)
What is the name of this molecule?
What is the name of this molecule?
What is the name of this molecule?
What is the name of this molecule?
What is the name of this molecule?
What is the generic mechanism for the electrophilic substitution with benzene?
Why are halogen carrier catalysts used in the electrophilic substitution of benzene?
What is the mechanism + conditions for Friedel Craft’s acylation?
Mechanism+conditions for friedel crafts alkylation?
Mechanism for addition of alcohol to a benzene ring using Friedel Crafts alkylation?
What is the mechanism for the nitration of benzene?
Below which temperature is a single NO2 substitution ensured in the nitration of benzene?
What is the general rule for numbering other groups in a phenol molecule?
Why are electrophilic substitution reactions more likely to occur in phenol than in benzene?
What is the equation of ethanoic anhydride and salicylic acid to give aspirin?
Why is ethanoic anhydride used in the synthesis of aspirin instead of ethanoyl chloride?
Are phenols acidic?
Yes. They are weak acids. They dissociate weakly to from a phenoxide ion and a H+ ion.
What is the equation for the reaction between phenol and NaOH?
What is the equation for the reaction between phenol and bromine water?
Which two isomers can be produced in the reaction of phenol with bromine water?
What are aliphatic amines?
How are aliphatic amines made by reacting a halogenoalkane with excess ammonia?
What is the downside of making aliphatic amines by reacting halogenoalkanes + excess ammonia?
What is the equation for making aliphatic amines using nickel catalyst and hydrogen to reduce nitriles?
What is the equation+conditions for making aliphatic amines using a strong reducing agent (LiALH4) and dilute acid?
What are the conditions+equation for aromatic amines?
What are the orders in the strength of the base in ammonia, primary aliphatic amines and aromatic amines?
Why are primary aliphatic amines more basic than NH3, and NH3 more basic than aromatic amines?
Can Amines hydrogen bond with water? How?
Are amines soluble in water? Why?
What happens when we react a small amount of butylamine with copper sulfate? What happens when the butylamine is in excess?
What is the equation for the reaction between ethanoyl chloride and butylamine?
What is different in the neutralisation recations of amines and acids from traditional acid-base reactions?
What is the equation for the reaction of butylamine with HCl?
What is the equation that shows how amines form an alkaline solution in water?
What are amides?
What are N-substituted amides?
What is the equation of ethanoyl chloride and ammonia?
What is the equation for the reaction between ethanoyl chloride and primary amines?
How are polyamides formed? Include equation.
What is the equation for the reaction that gives the polyamide Kevlar?
What is the equation to give the polyamide Nylon 6,6?
How are polyesters made? Give general equation.
What is the equation for the reaction that makes 1 repeating unit of the polyester terylene?
What is the general equation for the hydrolysis of a polyamide?
What is the general structure of an amino acid?
Are amino acids acidic or basic?
Are amino acids chiral?
How do you name this amino acid using the IUPAC rules?
What is a zwitterion?
What is the isoelectric point of an amino acid?
What is the general structure of an amino acid at their isoelectric point?
What is the general structure of an amino acid at pH lower than its isoelectric point?
What is the general structure of an amino acid at pH higher than its isoelectric point?
How does thin layer chromatography work?
Are Rf values fixed for each amino acid?
How are Rf values of Amino Acids calculated in thin layer chromatography?
How are Grignard reagents made?
What is the reaction of Grignard reagent with aldehydes + ketones?
What is the reaction of Grignard reagent with carbon dioxide?
Give eqt + conditions
What is the functional group, its properties and tipical reactions of halogenoalkanes?
What is the functional group, its properties and tipical reactions of nitriles?
What is the functional group, its properties and tipical reactions of amines?
What is the functional group, its properties and tipical reactions of aldehydes+ketones?
What is the functional group, its properties and tipical reactions of carboxylic acids?
What is the functional group, its properties and tipical reactions of esters?
What is the functional group, its properties and tipical reactions of acyl chlorides?
What is the functional group, its properties and tipical reactions of acid anhydrides?
What functional groups are present?
What functional groups are present?
What functional groups are present?
What are addition reactions?
What are substitution reactions?
What are elimination/dehydration reactions?
What are condensation reactions?
What are hydrolysis reactions?
What are oxidation reactions?
What are reduction reactions?
What conditions are A?
What conditions are B?
What conditions are C?
What conditions are D?
What conditions are E?
What conditions are F?
What conditions are G?
What conditions are H?
What conditions are I?
What conditions are J?
What conditions are K?
What conditions are L?
What conditions are M?
What conditions are N?
What conditions are O?
What conditions are P?
What conditions are A?
What conditions are B?
What conditions are C?
What conditions are D?
What conditions are E?
What conditions are F?
What conditions are G?
What conditions are H?
What conditions are I?
What conditions are J?
What conditions are K?
What conditions are L?
What conditions are A?
What conditions are B?
What conditions are C?
What conditions are A?
What conditions are B?
What conditions are A?
What conditions are B?
How is heating under reflux done?
How is distillation done to separate substances with different bpts?
How is steam distillation done?
How does vacuum filtration work?
How is recrystallisation done?
