1. www.soran.edu.iq Organic chemistry Assistance Lecturer Amjad Ahmed Jumaa  Alkyl group alkane 1

2. www.soran.edu.iq Alkyl groups  A primary carbon directly attached to one other carbon.  A secondary carbon directly attached to two other carbon.  A tertiary carbons to three other carbons.

3. www.soran.edu.iq 3 Alkanes  The family of alkanes forms such a homologous series, the constant difference between successive members being (CH 2 ).  hydrogen atoms equals two more than twice the number of carbons atoms.  formula for this series is: C n H 2n+ 2. Alkanes  The family of alkanes forms such a homologous series, the constant difference between successive members being (CH 2 ).  hydrogen atoms equals two more than twice the number of carbons atoms.  formula for this series is: C n H 2n+ 2.

4. www.soran.edu.iq  The following table (1) gives the first twenty alkanes: 7

5. www.soran.edu.iq  The alkane's methane, ethane, propane, butane, and pentane have respectively one, two, three, four, and five carbon atoms.  We also see the names are derived from the Greek (or Latin) prefix for the particular number of carbons in the alkanes: Pentane = for five carbon atoms. Hexane = for six carbon atoms. Heptane = for seven carbon atoms. Octane= for eight carbon atoms. And so on.

6. www.soran.edu.iq 6 Problem: when n=5 give the name of the alkane and write its structure? Solution: according to the general formula C n H 2n+ 2. Cx 5 H 2 x 5+2 C 5 H 12. The alkane is pentane.and the structure is: CH 3 CH 2 CH 2 CH 2 CH 3 Follow problem: give the structural formula and the name for the alkane when n=9

7. www.soran.edu.iq 7 Follow problem: give the structural formula and the name for the alkane when n=6 Follow problem: for structural formula: CH 3 CH 2 CH 3 write the general formula? Then determine the ( n value).