1.  How many different alkanes with C₆H₁₄ molecular formula can you make? Draw their skeletal formulae and name them.

 

 

2.  What is the shortest chain-length alkane to have structural isomers ?       

butane – which has the isomer methylpropane

 

3.  Draw all the isomers of C₄H₈ you can think of. Which can have cis-trans isomers ?

 

4. Draw skeletal formulae of cis-hex-3-ene and trans-hex-3-ene

5.  Which of the following molecules has chiral centers, and where are they?

CH₃CH₂CH₂CH­₂CH­₂OH     no chiral centre

CH₃CH₂C*H(NH₂)CH₃          chiral centre shown by *

CH₃CHClCH₃                             no chiral centre

CH₃C*H(OH)Br                     chiral centre shown by *

CH₃CH(CH₃)C*H(OH)C*H(CH₃)CH₂CH₃      two chiral centres each shown by *

6.  Draw the optical isomers of serine,  H₂NCH(CH₂OH)COOH