video 14.1 introduction to organic chemistry

Transcription

1 video 14.1 introduction to organic chemistry organic chemistry Organic ompound: contains and YDROGEN Major sources of organic compounds are: petroleum, coal, wood, plants, animals 1

2 properties of carbon arbon has valence electrons. Therefore, it will bond times to achieve a stable octet. organic molecules Sometimes double and triple bonds are needed to fulfill all octets A double bond shares electrons. A triple bond shares electrons. 2

3 properties of organic compounds Generally INSOLUBLE in water ( Like dissolves like ) SOLUBLE in nonpolar substances conductors of electricity (nonelectrolytes) because they do not form ions properties of organic compounds melting/boiling points due to INTERMOLEULAR forces (don t get bonds and intermolecular forces confused the covalent bonds between atoms are strong, the intermolecular forces between molecules are weak) ombustible (flammable) 3

4 hydrocarbons Organic compounds that ONLY contain ARBON and Alkanes hydrocarbons that contain only bonds (saturated) saturated-single bonds Alkenes hydrocarbons that contain a bond (unsaturated) Alkynes hydrocarbons that contain a bond (unsaturated) table q Table Q omologous Series of ydrocarbons Name General Examples Formula Name Structural Formula alkanes n 2n+2 ethane alkenes n 2n ethene alkynes n 2n 2 ethyne Note: n = number of carbon atoms 4

5 table p Table P shows prefixes to determine how many atoms a compound has Table P Organic Prefixes Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 dec- 10 Number of arbon Atoms Give the prefix for the following: example Table P Organic Prefixes Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 dec- 10 Number of arbon Atoms 5

6 naming hydrocarbons Table P ombine the information from Tables P & Q. Table Q omologous Series of ydrocarbons Name General Examples Formula Name Structural Formula alkanes n 2n+2 ethane alkenes n 2n ethene alkynes n 2n 2 ethyne Note: n = number of carbon atoms Organic Prefixes Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 dec- 10 Number of arbon Atoms naming hydrocarbons Table P ombine the information from Tables P & Q. Table Q omologous Series of ydrocarbons Name General Examples Formula Name Structural Formula alkanes n 2n+2 ethane alkenes n 2n ethene alkynes n 2n 2 ethyne Note: n = number of carbon atoms Organic Prefixes Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 dec- 10 Number of arbon Atoms 6

7 determining type of hydrocarbon when given formula Use Table Q ount up the number of carbons If the # of s are double the # of s, its an alkene If s more than double s, its an alkane Less than double, its an alkyne Table Q omologous Series of ydrocarbons Ex Name General Examples Formula Name Structural Formula alkanes n 2n+2 ethane alkenes n 2n ethene alkynes n 2n 2 ethyne Note: n = number of carbon atoms example: naming hydrocarbons Table P Organic Prefixes Table Q omologous Series of ydrocarbons Name General Examples Formula Name Structural Formula alkanes n 2n+2 ethane alkenes n 2n ethene alkynes n 2n 2 ethyne Note: n = number of carbon atoms Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 dec- 10 Number of arbon Atoms 7

8 video 14.2 structural formulas types of formulas Molecular Formula shows the # of atoms of each element in a compound Structural Formula diagram of the structure of a compound ondensed Structural Formula each carbon is written separately followed by the atoms to it

9 drawing structural formulas for alkanes Use Tables P & Q to determine # of ARBON and YDROGEN REMEMBER: Each arbon must have bonds example Formulas for Methane Molecular: 4 Structural: 9

10 Formulas for Ethane Molecular: 2 6 example Structural: drawing structural formulas for alkenes Same as alkanes except If there are more than 3 carbons, you need to give the location of the double bond with a number Always START numbering the carbons at the end LOSEST to the double bond to give the double bond the lowest number Molecules can be read left to right or right to left 10

11 Formulas for Ethene Molecular: 2 4 example Structural: example Formulas for Propene Molecular: 3 6 Structural: 11

12 example Formulas for 1-butene Molecular: 4 8 Structural: example Formulas for 2-butene Molecular: 4 8 Structural: 12

13 drawing structural formulas for alkynes Same as alkenes except you add a TRIPLE BOND example Formulas for 1-butyne Molecular: 4 6 Structural: 13

14 example Formulas for 2-butyne Molecular: 4 6 Structural: video 14.3 branched hydrocarbons 14

15 branched hydrocarbons naming branched alkanes When naming branched alkanes, name the longest chain of and use that as the last name. Then name the shorter chains, specifying the position of each branch. Make sure that your branches are numbered as low as possible (remember you can count your carbons from right to left or left to right). 15

16 locating the parent chain Find the longest chain of carbons that are connected to one another (they don t necessarily have to be in a straight line) Ex. naming branches ount # of arbons in branch Use prefix from Table P Add suffix yl to prefix Ex. 3 = Methyl Table P Organic Prefixes Prefix meth- 1 eth- 2 prop- 3 but- 4 pent- 5 hex- 6 hept- 7 oct- 8 non- 9 Number of arbon Atoms dec

17 example: branched alkane Step 1: Find the longest continuous chain of carbons (parent chain) There are 7 continuous carbons, so the parent chain is: example: branched alkane Step 2: Number the carbons in parent chain starting with the end that will give the attached groups the smallest #. 17

18 example: branched alkane Step 3: Figure out the names of the attached branches. example: branched alkane Step 4: Add numbers to the names of the groups to identify their positions on the chain and list the groups in alphabetical order. 18

19 example: branched alkane Step 5: Use punctuation: ommas separate numbers from numbers yphens separate numbers from words example 2: branched alkane **Use prefixes if the same group appears more than once in the structure. Di = twice Tri = three times Tetra = four times Penta = five times 19

20 example 2: branched alkane Step 1: ount the carbons name the parent chain. Step 2: Number carbons so attached groups have smallest numbers. example 2: branched alkane Step 3: Figure out names of attached branches. Step 4: Add numbers to names based on position on parent chain and list in alpha order 20

21 example 2: branched alkane Step 5: Add punctuation. example 3: branched alkane Name this compound: 21