Question

Draw the structures for the following compounds.
(i) Ethanoic acid , (ii) Bromopentane
(iii) Butanone , (iv) Hexanal

Answer 1

(i) `underset("Ethanoic acid")(H-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-OH" or "CH_(3)-overset(O)overset(||)(C)-OH`
(iii) `underset("Bromopentane")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-Br)" or "CH_(3)-CH_(2)-CH_(2)-CH_(2)-CH_(2)-Br`
(iii) `underset("Butanone")(H-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H)" or "H_(3)C-overset(O)overset(||)(C)-CH_(2)-CH_(3)`
(iv) `underset("Hexanal")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-H)" or "CH_(3)-CH_(2)-CH_(2)-CH_(2)-CH_(2)-overset(O)overset(||)(C)-H`
Bromopentane has a chain of five carbon atoms. it can exist in a number of forms which are structural isomers.
(i) `underset("1-Bromopentane")(H_(3)overset(5)(C)-overset(4)(C)H_(2)-overset(3)(C)H_(2)-overset(2)(C)H_(2)-overset(1)(C)H_(2)-Br)`
(ii) `underset("2-Bromopentane")(H_(3)overset(5)(C)-overset(4)(C)H_(2)-overset(3)(C)H_(2)-underset(Br)underset(|)overset(2)(C)H-overset(1)(C)H_(3)`
(iii) `underset("3-Bromopentane")(H_(3)overset(5)(C)-overset(4)(C)H_(2)-underset(Br)underset(|)overset(3)(C)H-overset(2)(C)H_(2)-overset(1)(C)H_(3))`
(iv) `underset("1-Bromo-3-methylbutane")(H_(3)overset(4)(C)-underset(CH_(3))underset(|)overset(3)(C)H-overset(2)(C)H_(2)-overset(1)(C)H_(2)-Br)`
(v) `underset(1-"bromo-2-methylbutane")(overset(4)(C)H_(3)-overset(3)(C)H_(2)-underset(CH_(3))underset(|)overset(2)(C)H-overset(1)(C)H_(2)-Br)`
(vi) `underset("1-Bromo-2,2-dimethylpropane")(overset(3)(C)H_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(.^(2)C)-overset(1)(C)H_(2)-Br)`
* The structural isomers (i),(ii) and (iii) Which differ in the position of the Br atoma re known as postion isomers
* The structural isomers (iv), (v) and (vi) which differ in the arrangement of carbonatoms in the chain are called chain isomers.
* In writing the IUPAC name, the name of prefix of prefix bromo is written before that of prefix methy. In fact, alphabetical order is followed while naming the different prefixes