Answer
See the following structure for each alcohol:
Work Step by Step
Question a: Pent means 5. So, no. of C in straight chain is 5. Step 1: Draw 5 C in a straight line and join them with single bond and numbering 1 to 5 from left to right. Step 2: ending name is 'anol'. It means there is an OH group will be at 3rd position (because the name suggests 3-pentanol). Add OH group as a substitute on no. 3 Carbon. Step 3: Fill the remaining valency of C with Hydrogen atom.
Question b: Step 1 - 'but' means 4. Draw 4 C in a straight line and join them with single bond and numbering the C from right to left. Step 2: Add methyl group on no. 2 Carbon (as the name suggests 2-methyl) and add OH group on 1st Carbon (as the name suggests 1-butanol). Step 3 - Fill the remaining hands of C with H atom.
Question c: Step 1 - 'hex' means 6. Draw 6 C in a straight line and join them with single bond and numbering the C atoms from left to right. Step 2: Add ethyl group on no. 3 Carbon and OH group on no. 2 Carbon as substitute (as the name suggests 3-ethyl-2-hexanol). Step 3: Fill the remaining hands (valency) of C with H atom.
Question d: Step 1 - 'eth' means 2. Draw 2 C in a straight line and join them with single bond and numbering them from right to left. Step 2: Add OH group on no. 1 Carbon. Step 3: Fill the remaining valency of C with H atom.
See the steps in picturized form below:
