Question

the wavelength value for Ethene is 175 nm various that for 1 3 butadiene is 217 nm​

Answer 1

Hey dear,

● Explanation -
- Let λmax be the wavelength of transition.
- λmax depends upon energy gap between highest occupied molecular orbital & lowest occupied molecular orbital.
- This energy gap is larger in ethene than that of 1,3-butadien
- This more energy required for transition is provided by smaller wavelength.
- Therefore, λmax for ethene (175 nm) is smaller than λmax for 1,3-butadiene (217 nm).

Hope this helped...