Quiz - Alkenes - 2 | Alkenes

Organic Chemistry 2 - Quiz - Alkenes - 2


What is the correct IUPAC name for the compound CH3CH=CHCH3?

The correct IUPAC name is 2-butene because the double bond starts at the second carbon when numbering from the end closest to the double bond, which gives the lowest possible numbers to the substituents.


How does the presence of a π bond affect the geometry around the double bond in an alkene?

π bonds in alkenes result from the overlap of p orbitals, leading to sp2 hybridization and a trigonal planar geometry around the double-bonded carbon atoms. This restricts rotation around the double bond compared to single bonds in alkanes.


Which statement about the π bond in alkenes is true?

π bonds are formed by the side-to-side overlap of p orbitals, which is different from σ bonds formed by end-to-end overlap. π bonds are weaker than σ bonds and restrict rotation around the double bond.


Which physical property of alkenes generally increases as the number of carbon atoms in the molecule increases?

The melting point of alkenes generally increases as the number of carbon atoms increases due to greater van der Waals forces, which require more energy to overcome.


Which reaction is commonly used for the laboratory preparation of alkenes?

Dehydrohalogenation of alkyl halides using a strong base is a common method for the laboratory preparation of alkenes, as it involves the elimination of a hydrogen halide.


What is the degree of unsaturation for a molecule with the formula C7H12?

The degree of unsaturation can be calculated using the formula (2C + 2 + N - X - H)2. For C7H12, the degree of unsaturation is 2, indicating two π bonds or rings.