Naming, Drawing, and Structural Formulae for Alkanes Structures of Alkanes Naming, Drawing, and Structural Formulae for Alkanes

Alkanes CH4 Also known as saturated hydrocarbons Made on C and H In hydrocarbons C is bonded to H and maybe C while H is only bonded to C C has 4 valence electrons and needs to share another 4 electrons to make an octet Consider Methane with the formula CH4 this is the simplest alkane CH4 Lewis dot structure Complete Structural formula Condensed structural formula 3-dimensional structure

Names of Alkanes The names all end in “ane”, the prefix depends on how many carbons are in the alkane

Constitutional Isomers When the molecular formula can be drawn with different structures Consider butane C4H10 geometric formula complete structural formulae

Cycloalkanes In a cycloalkane a group of C atoms form a ring Consider Cyclobutane C4H8 Complete Structural Formula Geometric Formula Condensed Formula 3-dimensional structure

Haloalkanes In a haloalkane a halogen like Cl or Br replaces one of the H atoms in the alkane CH3Cl Chloromethane BrCH2CH2Br 1,2 dibromoethane

B. Constitution isomers A. Structure of Alkanes Make a model and write out (i) the 3-d structure, (ii) complete structure formula and (iii) condensed structural formula for CH4 (methane), C2H6 (ethane), and C3H8 (propane) B. Constitution isomers C4H10 (butane), and 2-methyl-propane (isobutane) The 3 isomers of pentane C5H12 C. Cycloalkanes A ring structure involving 3 carbon atoms A ring structure involving 5 carbon atoms D. Haloalkanes Chloromethane, 1,2 dibromoethane, 2-iodopropane, 4 isomers of dichloropropane