u2 unknowns Flashcards
what is the type of reaction that occurs when a bromoalkane reacts with potassium hydroxide dissolved in ethanol?
elimination
what is created when a monohaloalkane is reacted with alcoholic alkoxides?
ethers
how are alkoxides formed?
by adding an alkali metal such as sodium or potassium, to an alcohol such as methanol or ethanol.
example of the formation of alkoxides
sodium added to methanol forms…
sodium methoxide and hydrogen
what is a methoxide ion capable of acting as?
a nucleophile
formation of alcohols via monohaloalkane nucleophillic substitution
monohaloalkane undergoes nucleophilic substitution when refluxed with an alkali. The hydroxide ion from the alkali acts as a nucleophile and attacks the carbon attached to the halogen. A halide ion is formed as the two bonding electrons in the carbon-halogen bond then move on to the halogen atom.
formation of nitriles
monohaloalkanes can undergo nucleophilic substitution reaction with ethanolic cyanide to form nitriles.
as a result of a reaction, the chain length increases by one carbon atom.
what is formed when nitriles are hydrolysed?
carboxylic acid.
formation of ethers
when a monohaloalkane is reacted with alcoholic alkoxides to form ethers.
when 1 bromobutane is reacted with potassium methoxide, what is the name of the ether formed?
methoxybutane.
what is required to eliminate a hydrogen halide from a monohaloalkane to form an alkene?
KOH dissolved in hot ethanol
hot ethanol must be used so that elimination is promoted over nucleophilic substitution.
which reagent can be used to convert carboxylic acids into alkanals?
lithium aluminium hydride
which base is the strongest?
C4H9NH2
NH3
C2H5NH2
CH3NH2
C4H9NH2
state the conditions and reagents required for the nitration of benzene?
conc H2SO4 + conc HNO4 refluxed at 50 degrees
requirements for bromination of benzene
AlBr3/Br2
or
FeBr3/Br2
requirements of alkylation of benzene
R-Cl/AlCl3
requirements of chlorination of benzene
AlCl3/Cl2
or
FeCl3/Cl2
requirements for nitration of benzene
conc HNO3 and conc H2SO4
reflux @ 50°C
requirements for sulfonation of benzene
conc H2SO4 reflux
what is LiAl4?
lithium aluminium hydride
a STRONG reducing agent commonly used in organic reactions
therefore it is used to convert carboxylic acids to aldehydes or alcohols.
what type of reaction does benzene take part in?
electrophillic SUBSTITUTION
how does the strength of the magnetic field affect the energy difference between spin states in NMR?
the stronger the magnetic field, the greater the energy difference between them
why does the chemical shift decrease as more hydrogens are attached?
the more hydrogens attached, the greater the shielding (as greater electron density) and the less the magnetic force will be felt, thus the smaller chemical shift.
when an acid is diluted, what decreases?
H+ ion concentration
what catalyst is used for the hydrolysis of a nitrile to form a carboxylic acid?
aqueous acid or strong base
what catalyst is used for the hydrolysis of an amid to form a carboxylic acid?
aqueous acid or strong base