Module 4

• What is the general formula for cycloalkanes

  $C_nH_{2n}$

  This is the same general formula as alkenes but they are considered alkanes as there are no double bonds present
• What is nomenclature

  The system used for naming compounds
• If something is described as aliphatic, what does that mean

  It is a hydrocarbon with carbon atoms attached in a straight or branched chain
• If something is described as alicyclic, what does that mean

  It is a hydrocarbon with carbon atoms joined in a ringed structure
• If something is described as aromatic, what does that mean

  It is a compound containing at least one benzene ring
• What is a saturated substance

  A compound with no double bonds present
• What is an unsaturated substance

  A compound with one or more double bonds present
• What is a homologous series

  A series of organic compounds that have the same functional group with successive members differing by CH_2
• What are the rules for naming branched hydrocarbons

  • Find and name the longest continuous chain of carbons (does not have to be a straight chain) and number it
  • Identify and name the groups attached to this chain
  • Designate the location of each attached group with an appropriate number (starting at the end where an attached group is closest) and name (forming the prefix)
  • Assemble the name with groups listed in alphabetical order
• What is a functional group

  A group of atoms responsible for the characteristic reactions of a particular compound
• When should you uses commas and dashes when naming compounds

  Commas - between numbers

  Dashes - between numbers and letters
• What is the empirical formula of a molecule

  The simplest whole number ratio of the atoms in a compound
• What is the molecular formula of a molecule

  The actual number of atoms in a compound
• What is the general formula of a molecule

  An algebraic formula for a homologous series
• What is the structural formula of a molecule

  It shows the position of the elements in a compound but not all of the bonds present

  EXAMPLE:

  $CH_3CH_2CH_3$
• What is the display formula of a molecule

  A diagram where all bonds between elements are shown
• What is the skeletal formula of a molecule

  A diagram that shows the carbon backbone of a molecule
• How do you represent branched groups in structural formula

  You put them in brackets after the carbon they are attached to

  EXAMPLE (methyl group on carbon-2):

  $CH_3CH(CH_3)CH_2CH_3$
• How do you construct a skeletal formula

  • each point 'represents' a carbon
  • don't draw hydrogens
  • only part represented with symbols are functional groups
• What is the functional group of an aldehyde

  A carbon - oxygen double bond at the end of a hydrocarbon chain
• What do all aldehydes end in

  -al (eg butan-al)
• What is the functional group of a carboxylic acid

  -COOH

  There is a double bond between one oxygen and the carbon

  The other oxygen and the hydrogen form an -OH group and come off the carbon
• What do all carboxylic acids end in

  -oic acid
• What is the functional group of an alcohol

  -OH group
• What do all alcohols end in

  -ol
• What is the functional group of a ketone

  A carbon - oxygen double bond in the middle of a hydrocarbon chain
• What do all ketone hydrocarbons end in

  -one
• What is the functional group in an alkene

  A carbon - carbon double bond
• What do all alkenes end in

  -ene
• Which functional groups have to have the carbon they are one specified

  • alcohols (eg propan-2-ol)
  • ketone (eg propan-2-one)
  • alkenes (prop-2-ene)
• Why is propan- used instead of prop- when naming a hydrocarbon (3 carbons in this example but the rule applies everywhere) with a functional group

  All suffixes for their respective functional groups start with a vowel
• What is a structural isomer

  A molecule with the same molecular formula, but different a structural formula
• What are the three types of structural isomerism

  • chain -> the alkyl groups are in different places
  • positional -> functional groups are bonded to different parts of parent chain
  • functional group -> different functional groups
• What is homolytic fission

  When a covalent bond breaks and each of the bonded atoms takes one of the two electrons in the bond
• What is a radical

  A species with a single unpaired electron
• This is how a radical is represented (by a dot next to the atom)

  
• What is heterolytic fission

  When a covalent bond breaks, one atom takes both of the electrons in the bond
• What does a curly arrow represent

  The movement of a pair of electrons
• How is electronegativity relevant to heterolytic fission

  This usually determines which atom will get both electrons
• What is an electrophile

  An electron pair acceptor (therefore it is positively charged)