CHEMISTRY COMMUNITY

Why are long bonds weaker than short bonds?

Long bonds are weaker than short bonds because the nuclei are farther apart so there exists less attractive pull. It is easier to break apart a bond when the atoms are farther apart.

Bond strength is described as the energy required to break the bond. As the bond length gets longer, the attraction the two bonding atoms impose on the bonding electrons becomes weaker and lowers the energy needed to break the bond. Thus, longer bonds are easier to break than shorter bonds are.

This is why acids with longer bonds are stronger, while acids with shorter bonds are acids. Strong acids with weak/long bonds can dissociate completely while weak acids with short/strong bonds cannot.

Since long bonds are farther away from the nuclei, it is easier to remove H+ so thus long bonds are strong acids. Conversely, short bonds are harder to break so they are weak acids.

Bond strength relates to how easy it is to pull electrons away from an atom. In regards to acids, strong acids are when bonds are further apart, making it easier for the electrons to be donated.

Strong acids are defined as those that can dissociate by donating an H+ and therefore a long bond which is farther apart and weaker (easier to break) allows for this while a shorter bond doesn't considering it is stronger therefore harder to break.

Abigail Menchaca_4H wrote:Why are long bonds weaker than short bonds?

short bonds are stronger than long bonds as the bond itself is shorter due to a stronger attraction between the two atoms of the molecule

what is they have the same bond length?

Long bonds are weaker than short bonds because they have less attraction to each other in contrast with short bonds. The atoms are either larger in size or the electrons are repelling each other away making it easy to break the bonds.