Draw all the possible noncyclic structural isomers of $\mathrm{C}_{5} \mathrm{H}_{10}$ Name each compound.

Structural isomers are molecules with the same molecular formula but different arrangements of atoms. They differ in their connectivity. In this case, we have C5H10, which is an alkene due to the presence of a double bond (general formula for alkenes is CnH2n).

Draw the five carbon atoms in a straight chain and place the double bond in different positions starting from the first carbon atom. 1. Double bond between C1 and C2 2. Double bond between C2 and C3 3. Double bond between C3 and C4. We won't consider a double bond between C4 and C5 because it has the same structure as the first double bond (between C1 and C2).

Draw the four carbon atoms in a straight chain and add a methyl group (CH3) as a substituent. Place the double bond in different positions and change the position of the methyl group as well: 1. Double bond between C1 and C2, with a methyl group on C3. 2. Double bond between C2 and C3, with a methyl group on C2. These are all the possibilities for noncyclic structural isomers of C5H10.

1. Isomer 1: Double bond between C1 and C2 of the 5-carbon chain. Name: \(Pent-1-ene\) Structure: CH2=CH-CH2-CH2-CH3 2. Isomer 2: Double bond between C2 and C3 of the 5-carbon chain. Name: \(Pent-2-ene\) Structure: CH3-CH=CH-CH2-CH3 3. Isomer 3: Double bond between C3 and C4 of the 5-carbon chain. Name: \(Pent-2-ene\) Structure: CH3-CH2-CH=CH-CH3 4. Isomer 4: Double bond between C1 and C2 of the 4-carbon chain with a methyl group on C3. Name: \(3-Methylbut-1-ene\) Structure: CH2=CH-CH(CH3)-CH3 5. Isomer 5: Double bond between C2 and C3 of the 4-carbon chain with a methyl group on C2. Name: \(2-Methylbut-2-ene\) Structure: CH3-C(CH3)=CH-CH3 So, there are 5 noncyclic structural isomers of C5H10: 1. Pent-1-ene 2. Pent-2-ene (two isomers with different arrangements) 3. 3-Methylbut-1-ene 4. 2-Methylbut-2-ene