Email from Professor. Wight :D

fromChuck Wight <chuck.wight@utah.edu>toAshlee Son <aliceandcrab@gmail.com>
dateSun, Oct 11, 2009 at 8:17 PMsubjectRe: hello professor wight.mailed-byutah.edu
hide details 8:17 PM (23 hours ago)
Hi Ashlee,
The statement that covalent bonds are stronger than hydrogen bonds is a generalization based on a large number of experimental measurements of bond dissociation energies.
There are many ways to do these measurements, including measuring the onset of bond breaking as a function of the wavelength of absorbed light.
For hydrogen bonds it is simple to measure the number of bonds broken as a function of temperature, because they are (usually) very weak. From this dependence, it is pretty easy to calculate the strength of the bonds. In the case of water, you can see that simply boiling the water breaks all of the bonds in the liquid to make isolated gas molecules. If water had covalent bonds it wouldn't boil but decompose into oxygen and hydrogen instead (probably).
Chuck Wight- Hide quoted text -

On Oct 10, 2009, at 7:16 PM, "Ashlee Son" <aliceandcrab@gmail.com> wrote:
- Hide quoted text -this is a some random korean high school student who is studying in Mt.Pleasant , Utah.while i was studying AP biology, i found the video that you were explaing about chemical bonding.I simply understand the chemical bonds and the differences between covelant, inoic, and hydrogen bonding.however i wonder how we know that covelant bonding is the strongest and hydrogen bonding is weakest,,i mean how people find out the fact? and how much is covelant bond stronger than other bonding?also how does the power of bonding affect? such as if hydrogen bonding is as strong as covelant bonding , it will changes some characteristic of water? i want to hear about more specific reason that i feel i totally understand. thank you !


Wow thank you so much prof.wight!