Organic chemistry Flashcards
(18 cards)
What is a nucleophile?
Negatively charged ion that donates electrons to the carbon
What is an electrophile?
Positively charged ion attracted to electrons in a double bond
What is heterolytic and homolytic fission?
Heterolytic is where the electron pair goes to one atom
X-Y —> (X+) + (Y-)
Homolytic fission is where each atom receives one electron from the bonded pair forming free radicals
What does free radical substitution form?
Turns alkanes into halgoenalkanes
What is reforming?
Turning alkanes into cycloalkanes or aromatic compounds
What is a sign and pi bond?
Sigma bond is overlap of orbitals and has high electron density so strong electrostatic attraction with the nuclei
Pi bond is weaker as overlaps sideways and has lower electron density
What is electrophillic addition used to make?
Alkene—> halogenalkane
How do you make an alcohol from an alkene?
Steam hydration (300 degrees c) Phosphoric (v) acid catalyst
How do you turn a halogenalkane into an alcohol?
Nucleophillic substitution
(Hydrolysing)
Needs water for alkali to dissolve in and heated under reflux
Iodine hydrolysed the fastest as it has lowest bond enthalpy
What is nucleophillic substitution used for?
Turning halogenalkane into an alcohol
How do you turn halogenalkane into alkene?
Elimination reaction
Needs potassium hydroxide
Needs ethanol
Heat under reflux
R-Cl +KOH —> R + KCl + H20
(Reflux +ethanol)
Making chloroalkanes from alcohol
PCl5
Making bromoalkanes from alcohol
Needs sulphuric acid and potassium bromide
Substitution reaction
Make iodoalkanes from alcohol
Need red phosphorus
PI3
Alcohols can be dehydrated to form alkenes
What type of reaction and condition?
Elimination reaction
Acid catalyst (Conc phosphoric acid)
Heat
Oxidation of primary alcohols
With k2Cr2O7 (potassium dichromate)
Makes aldehydes then carboxylic acid
Oxidation of secondary alcohols
With k2Cr2O7 (potassium dichromate)
Under reflux
Makes ketone
Oxidation of tertiary alcohols
Not easily oxidised
