1.Structural isomer refers to organic compound that have the same molecular formula but different structure (bonding pattern is different). This problem is designed to guide you to explore structure isomer.
(a)Go ahead and write Lewis structure for butane (C4H10). You may draw four C atoms connect straight as like in train.
(b)In the above structure, four C atoms are connected straight in a line. If you move one C atom to the side (like 3 C atoms in a line, one connected to the middle C atom), after you supply all the H atoms to make all the C atoms saturated with 4-bonds each. Will the molecular formula for your structure drawn be different from butane?
( c) Structures you obtained in (a) and (b) are an example of structural isomers. What kind of name we can give to structure in (b) so we can differentiate it from structure in (a)?
2.Alkane is the basic building block of organic compound. We often write alkane chain as a group R. On this basic chain, we can add different functional group, like âOH for alcohol, -COOH for carboxylic acid.
(a)Methanol refers to CH3OH. Ethanol refers to CH3CH2OH. Draw the Lewis structure for these two compounds.
(b) If you have a straight alkane chain, where does âOH group can be attached? How do you name it so you can know where âOH group is attached?
3. Give the Lewis structure for CH3COOH. Give its systematic name and common name.
4. Ester refers to two alkane chains connected through a single O atom. Write the Lewis structure for this simplest kind of ester: CH3OCH3. Find its name and some common use.
5. Benzene molecular formula is C6H6. The six carbon atoms are connected to form a ring (hexagon). Draw the Lewis structure for C6H6. Do you think the six bond lengths between C-C atoms should be same or not according to your drawn Lewis structure?
