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K: Welcome to Chemistry Talk, where we have fun with chemistry!! I'm one of your hosts
Kelli, and this is my co-host Vu! V: Hello!
K: As always, our sponsor for today's episode is gas - the stuff that you breathe!
V: Today we will be discussing Hydrogen Bonding! K: Hydrogen bonding is a very important part
of our daily lives. It is a part of the water we drink, and even our very DNA.
V: First, let's define Hydrogen Bonding. Hydrogen Bonding is an intermolecular force formed
when a Hydrogen bonded to a very electronegative atom is attracted to a lone pair on another
electronegative atom. K: What electronegative atoms might these
be, you ask? There are three highly electronegative atoms: Nitrogen...Oxygen...and Fluorine!
V: When the Hydrogen and the lone pairs get close enough together, they are attracted
to each other and pull towards one another, much like these magnets.
K: The individual bond they form isn't so strong that it can't easily break. But together,
many hydrogen bonds can be very strong. V: For example, when you compare the boiling
points between pure substances of proplyamine and trimethylamine, the difference in boiling
points is 46 degrees Celsius, though they have the same number of bonds and molecules!
K: Here you can see the Hydrogen attached to the Nitrogen on the propylamine, and the
lone pair that would interact with lone pairs on other electronegative atoms, like on this
oxygen on this water molecule. V: But Hydrogen bonding is important in many
larger molecules too! K: For example, the Hydrogen bonds between
Nitrogenous bases in DNA create the signature Double Helix structure. These Hydrogen bonds
can also split apart and re-form during DNA replication! Cool, huh?
V: Well, that's it for today's Hydrogen bonding presentation!
K: Thank you for watching!