Question 22.4: Give the structural formula for the alkene with the IUPAC na...

1. Start with the parent hydrocarbon. Pent means 5, so draw a five-carbon chain.
-C_{1}-C_{2}-C_{3}-C_{4}-C_{5}-
2. The suffix -ene means that there is a double bond, and the number 2 before the hydrocarbon means that the double bond is inserted at C_{2} position.
-C_{1}-C_{2}=C_{3}-C_{4}-C_{5}-

3. The number 3 before the word ethyl means that an ethyl group is bonded to C_{3}.
-C_{1}-C_{2}=\underset{\overset{|}{C_{2}H_{5}} }{C_{3}} -C_{4}-C_{5}-

4. Add the missing hydrogen atoms to get the final answer.