How does hyperconjugation affect bond lengths in alkenes? How does the number of hyperconjugates affect the $\ce{C=C}$ bond length in the compounds propene and 3,3-dimethylbut-1-ene?



In general, is bond length directly or inversely proportional to the number of hyperconjugates?
The higher the number of alpha hydrogens present in a molecule, the more resonance there will be which will decrease the bond order which was earlier 2, thus decreasing its strength and increasing its length.