5) mathrm(CH)_(3)-mathrm(CH)-mathrm(CH)_(2)-mathrm(C)=mathrm(CH)_(2)

The given compound is .This compound is an alkene, which is a type of hydrocarbon with a carbon-carbon double bond. In this case, the double bond is located between the second and third carbon atoms.The name of this compound is 1-pentene. It consists of a five-carbon chain with a double bond between the first and second carbon atoms.The molecular formula of 1-pentene is .In summary, the given compound is 1-pentene, which is an alkene with a five-carbon chain and a double bond between the first and second carbon atoms.