How is propene more reactive as well as more stable than ethene?

I know that hyperconjugation stabilises a double bond. But in propene an electron-donating group $(\ce{-CH3})$ is increasing the electron density at the double bond, so its nucleophilicity should be higher. How can it be more stable as well as more reactive?




you need to go with the mechanism.


1st


[![enter image description here](https://i.stack.imgur.com/EOj8u.png)](https://i.stack.imgur.com/EOj8u.png)


in this case **propene will form a 2nd degree carbocation which is more stable.**


2nd
[![enter image description here](https://i.stack.imgur.com/3MEWP.png)](https://i.stack.imgur.com/3MEWP.png)


when the electrophile is having a lone pair then a 3 membered ring is formed as intermidiate.then the other Nucleophile attack to open the ring and thus product is formed.


you can refer to Markovnikov's Rule for further info(<https://en.wikipedia.org/wiki/Markovnikov%27s_rule>)


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