chemistry paper 2

• What is a hydrocarbon?

  A compound consisting of hydrogen and carbon only
• What is a molecular formula?


  The formula which shows the actual number of each type of atom
• What does it mean if a compound is unsaturated?

  It contains a C=C double bond
• What does it mean if a compound is saturated?

  It contains single carbon-carbon bonds only
• What is a general formula in organic chemistry?


  An algebraic formula for a homologous series, e.g., CnH2n
• What is an empirical formula?

  It shows the simplest whole number ratio of atoms of each element in the compound
• What is a displayed formula?

  • Shows all the covalent bonds and atoms present in a molecule
  • Used to represent the structure of organic compounds
• How should hydrogen atoms be added when drawing organic compounds?

  So that each carbon has 4 bonds
• What is the shape around the carbon atom in saturated hydrocarbons?

  The shape is tetrahedral with a bond angle of 109.5°
• What is a skeletal formula?

  • A simplified organic formula
  • Shows the carbon skeleton and associated functional groups
  • Hydrogen atoms are removed from alkyl chains
• What is a structural formula?


  • Shows the minimal detail of the arrangement of atoms in a molecule
  • Example for butane: CH3CH2CH2CH3 or CH3(CH2)2CH3
• What is a functional group?

  An atom or group of atoms that causes different molecules to have similar chemical properties
• What are homologous series in organic chemistry?

  • Families of organic compounds with the same functional group
  • Same general formula
  • Show gradual changes in physical properties (e.g., boiling point)
  • Each member differs by CH2 from the last
• What are the suffixes and prefixes for different functional groups in organic compounds?

  • Alkanes: -ane
  • Alkenes: -ene
  • Alcohols: -ol (hydroxy-)
  • Halogenoalkanes: chloro-, bromo-, iodo-
  • Aldehydes: -al (formyl-)
  • Ketones: -one (oxo-)
  • Carboxylic acids: -oic acid
  • Esters: -yl –oate
• How do you name a branched chain in organic chemistry?

  Add the appropriate prefix for each branch chain
• What is the order of priority for naming functional groups?

  Carboxylic acids > aldehydes > ketones > alcohols > alkenes > halogenoalkanes
• What is the prefix for a one-carbon chain in organic chemistry?

  Meth-
• What is the prefix for a two-carbon chain in organic chemistry?

  Eth-
• What is the prefix for a three-carbon chain in organic chemistry?

  Prop-
• What is the prefix for a four-carbon chain in organic chemistry?

  But-
• What is the prefix for a five-carbon chain in organic chemistry?

  Pent-
• What is the prefix for a six-carbon chain in organic chemistry?

  Hex-
• What is the prefix for a seven-carbon chain in organic chemistry?

  Hept-
• What is the prefix for an eight-carbon chain in organic chemistry?

  Oct-
• What is the prefix for a nine-carbon chain in organic chemistry?

  Non-
• What is the prefix for a ten-carbon chain in organic chemistry?

  Dec-
• What are the general rules for naming carbon chains?

  • Count the longest carbon chain and name appropriately
  • Find any branched chains and count how many carbons they contain
  • Add the appropriate prefix for each branch chain
• How is the position of a functional group indicated in a carbon chain?

  By a number, counting from the end that gives the functional group the lowest number
• What is the rule for including numbers in naming organic compounds?

  Include numbers only if they are needed to avoid ambiguity
• What are the rules for using suffixes in naming organic compounds?

  • If the suffix starts with a vowel, remove the –e from the stem alkane name
  • If the suffix starts with a consonant or if there are two or more of a functional group, do not remove the –e from the stem alkane name
• How do functional groups affect the numbering in naming organic compounds?

  Functional groups take precedence over branched chains in giving the lowest number
• What is the correct name for 3,5-dimethylheptane?

  It indicates a heptane with methyl groups on the 3rd and 5th carbons
• What is the naming convention for halogenoalkanes?

  Class the halogen as a substituent on the carbon chain and use prefixes -fluoro, -chloro, -bromo, or -iodo
• What is the naming convention for alcohols?

  They have the ending -ol and the position number for the OH group is added if necessary
• How do you name alcohols with higher priority functional groups?

  The higher priority group gets the suffix ending, and the OH can be named with the prefix hydroxy-
• What is the naming convention for alkenes?

  The suffix -en can go in front of other suffixes
• How do you indicate the position of a double bond in alkenes?

  Use the lower number of the two carbons involved in the double bond
• What is the naming convention for aldehydes?

  An aldehyde’s name ends in –al
• Why does an aldehyde not need an extra number in its name?

  It always has the C=O bond on the first carbon of the chain
• What is the naming convention for ketones?

  Ketones end in -one