Heat weakening chemical bonds

goleynik

Does heat weaken the strength of chemical bonds?

chemisttree

It causes the molecule to vibrate severely and smash into things (other molecules) with more violence. What happens when you lightly tap a crystal glass with a small hammer vs swinging a sledge hammer at it?

goleynik

So do the bonds weaken or not?

chill_factor

ok. let me put it this way.

chemical bonds have a set enthalpy of formation; that's what's quoted as the bond strength and that depends only on the identity of the bond and the atoms that form it.

that said, heat "weakens" chemical bonds by making molecules easier to dissociate. you can think of it this way: chemical bonds are a form of negative energy. if you add energy, the energy is less negative. when the energy goes to 0, the molecule breaks apart.

heat is a form of energy. that means that it'll take less "other" energy to break the molecule apart. if you add enough heat the molecule breaks apart on its own.

chemisttree

No. Other forces overcome them.

goleynik

Why then if bonds can be broken with heat then why can't the bonds be weakened by heat.

chill_factor

ok. lets say you're stuck in a well with spring boots. jumping a bit at first, your legs are weak and you can't get out. someone gives you sugar drink and you have more energy so you can jump out.

Did the well weaken?

Einstein Mcfly

nice.