Organic chemistry

• Aldehydes


  Organic compounds with the general formula RCHO, where R is an alkyl group
• Aldehydes


  • Have a carbonyl group (C=O) at the end of the carbon chain
  • The carbon atom of the carbonyl group is attached to one hydrogen atom and one R group
• Ketones


  Organic compounds with the general formula RCOR', where R and R' are alkyl groups
• Ketones


  • Have a carbonyl group (C=O) within the carbon chain
  • The carbon atom of the carbonyl group is attached to two R groups
• The simplest ketone is Propanone (CH3COCH3), also known as acetone
• Acetone is widely used as an industrial solvent and in nail varnish removers
• Naming carbonyl compounds


  1. Add 'al' for aldehydes (e.g. propan-1-al)

  2. Add 'one' for ketones (e.g. propanone)
• Reaction of carbonyl compounds with acidified dichromate (VI) ions (Cr2O7^2-/H+)

  1. Mixture with [O] + reflux

  2. Nucleophile attracted to positive carbon of carbonyl group and attacks

  3. Results in addition across the C=O double bond
• The polarity of the C=O double bond is the reason for the nucleophilic addition reaction
• Nucleophilic addition


  Reactivity of
• Carbonyl group


  • Aldehydes and ketones
  • Influenced by the double bond
• Pi bond

  • Sideways overlap of p-orbitals
• Aliphatic haloalkanes


  Halogen is joined to a carbon chain
• Hydrolysis


  1. Aqueous solution

  2. Causes breaking of carbon-halogen bond

  3. Halogen atom replaced by nucleophilic -OH group

  4. Substitution reaction
• Nucleophilic substitution


  • Nucleophile approaches
  • Lone pair of electrons on nucleophile minimises repulsion with halogen
  • New bond formed between nucleophile and carbon
  • Carbon-halogen bond breaks by heterolytic fission
• Alcohol halide ion


  Formed in nucleophilic substitution
• Alkanes


  Strang, good, non polar, c-c and C-H bands, 4 makes em stable/unreact vecinant, c-e and Lalet of 716 bands high hand enthalpies, energy is needed to break Hen, heat, large amounts, energy is released, is stored in these heat
• Complete combustion: Alkane + oxygen


  Carbon dioxide & water
• Reactions OF Alkenes with halogens

  No Light ↳ Alkane + halogen No. UV light ↳ Alkane + halogen halodikare + hydrogen haside
• 4 causes a Fee radical chain reache called Substitution reaction
• Halogenation /Free radical subsitation happens via homolytic bond fission forming Free radicals


  Formed (uv Light initiation L - during this, free radicals are required) Free radicals are shown by ()E... 20- done by Homolytic band. atom receives one Fission (each bonding I election 2) Propagation Free radical and reacts with the Alkane more radicais are formed
• Step A CCHU CH3 + HCL

  • Hydrogen Lavide (Stable by product)) ( C Step 2: CH3 +CL2 (4-CL Alkyl Halogen Haloalkee radical (in excess) (desired 7444 Halide radical (very reactive))
• 1. Termination


  ↳ during this, the free racticals are destroyed. Two FO Form an radicals always join togethe 4 can happen of any point FI inert substance
• Chlorination CCM CHE + Hel


  • ethane, manes Chloroethane
• Alkenes


  Same as Alkanes but has a double bond, therefore each carbon has one less Hydrogen and is trigonal planar in shape
• Alkenes


  • Unsaturated, they can bond with at least one double C-C bond
  • Cyclic alkenes with more than one double bond follow the general formula CnH2n
• Sigma (σ) bond


  Overlap of orbitals
• Pi (π) bond


  Sideways overlap of orbitals
• The pi bond in alkenes is weaker than the sigma bond because it has a smaller head-to-head overlap
• Bromination of alkenes


  H2C=CH2 + Br2 → CH2Br-CH2Br