Hydrocarbons By Matt, Tina, and Stephen

Do Now Thanking about Organic chemistry in our daily life Objective Alkanes Straight chains /Chain structure/Branched Chains Naming carbon chains Homework Finish the worksheet, we will go over it next class

Do Now Have you ever heard of organic chemistry ? When? Can you think of anything related to it in our daily life ? Crude oil Coal Natural gas Gasoline Fuel ……

What are they? Simplest organic compounds Carbon, having 4 valence electrons, always forms 4 covalent bonds Ex:methane(CH4) and ethane(C2H6) Carbon able to form bonds with many different atoms, often hydrogen

Why are they important? Over nine million known organic compounds, all with hydrocarbon Found in fats and oils of your breakfeast The gasoline that powers your car is taken from petroleum, which contains hydrocarbon Clothing,plastics,fibers,medicine,insectisides

Alkanes Weak Van der Waals forces Lower molar masses mean lquid or gas at lower temperature Nonpolar molecules(don’t form solution with polar molecules) Hydrocarbon with only single covalent bonds Carbon atoms in alkanes can be straight or branched chains

Straight chains Changes reflect increase in molar mass Carbon atoms lined 1 after another Names have -ane suffixes, with number prefixes for compounds with 5 or more carbon atoms methane, CH 4 - one carbon and four hydrogen ethane, C 2 H 6 - two carbon and six hydrogen propane, C 3 H 8 - three carbon and 8 hydrogen butane, C 4 H 10 - four carbon and 10 hydrogen pentane, C 5 H 12 - five carbon and 12 hydrogen hexane, C 6 H 14 - six carbon and 14 hydrogenmethane ethane propane butane pentane hexane

Chain structure Heptane, or C7H16 The Carbon atoms are in a straight line, with hydrogen atoms around them Chains with at least 2 carbon atoms have 3 hydrogen atoms for the 1st and last atoms and 2 for all the others(ex hexane:CH 3 (CH 2 ) 4 CH 3 )

Branched Chains Carbon always forms 4 covalent bonds with something, when carbon bonds with 3 or 4 carbon atoms, branches are formed Substituent:substitute atom for hydrogen Alkyl group:hydrocarbon substituent that can be any amount of carbons in length, they are added to straight chains forming branched chains Named by largest continuinous carbon chain

Naming carbon chains IUPAC(International Union of Pure and Applied Chemistry) formula Find longest carbon chain(parent structure) in this case the 8 Carbon atoms Name it (8 carbons give it octane as a name) Find side chains (count carbon branching off of parent structure)

Naming carbon chains,cont Count the rooted chain to make the sum of the side groups as low as possible ( left to right would make them 2,3,and 4 while right to left would be 5,6, and 7) Change suffixes from -ane, to -yl(methane becomes methyl) number prefixes such as di and tri used should there be multiple side chains of the same type(2 methane chains; 2,4-dimethyl) Number of the carbon atom side chain attached to put before name(ex: 2-methyl,4,-ethyl,3- propyl) Use commas to separate numbers,and hyphens to separate numbers and words Put name chains in alphabetical order (excluding prefixes) before main chain(ethyl,methyl,propyl) This chain’s name is 4-ethyl-2-methyl,3-propyloctane

Problems Can you name these alkanes?

Resources Prentice Hall Chemistry(our textbook) Ausetute.com n.htmlhttp:// n.html organic-chemistry.htm

Homework Try your best to finish the work sheet, we will go over it the next class.