The presence of a double bond in an alkene molecule significantly affects the outcome of an electrophilic addition reaction compared to an alkane molecule. Here's why:1. Reactivity: Alkenes are more reactive than alkanes due to the presence of the double bond. The double bond consists of a sigma bond and a pi bond, where the pi bond is weaker and more exposed to electrophiles. This makes alkenes more susceptible to electrophilic addition reactions, whereas alkanes are relatively unreactive and require more extreme conditions to undergo reactions.2. Electrophilic addition mechanism: In an electrophilic addition reaction, the electrophile is attracted to the electron-rich double bond in the alkene. The pi electrons of the double bond form a new sigma bond with the electrophile, breaking the pi bond and creating a positively charged carbocation intermediate. A nucleophile then attacks the carbocation, forming a new sigma bond and resulting in the addition of the electrophile and nucleophile across the double bond. In contrast, alkanes do not have a double bond and do not undergo electrophilic addition reactions.3. Regioselectivity: The outcome of an electrophilic addition reaction on an alkene can be influenced by the structure of the alkene and the nature of the electrophile. According to Markovnikov's rule, when an unsymmetrical alkene reacts with an unsymmetrical electrophile, the electrophile will preferentially bond to the carbon with more hydrogen atoms, while the nucleophile will bond to the carbon with fewer hydrogen atoms. This leads to the formation of the more stable carbocation intermediate. Alkanes do not exhibit such regioselectivity as they do not undergo electrophilic addition reactions.4. Stereochemistry: Electrophilic addition reactions of alkenes can lead to the formation of stereoisomers, depending on the geometry of the alkene and the reaction conditions. For example, when a non-chiral electrophile reacts with a cis- or trans-alkene, two different stereoisomers can be formed due to the addition of the electrophile and nucleophile across the double bond. Alkanes do not have such stereochemical implications as they do not undergo electrophilic addition reactions.In summary, the presence of a double bond in an alkene molecule makes it more reactive and susceptible to electrophilic addition reactions, with outcomes influenced by regioselectivity and stereochemistry. Alkanes, on the other hand, do not have a double bond and do not undergo electrophilic addition reactions.