Ch 4 Pt 1 Notes
Card Set Information
Ch 4 Pt 1 Notes
what are free radicals?
very reactive intermediates
Bond dissociation energy?
how much energy is required to break a bond
Bond dissociation will tell us what?
whether it is exothermic versus endothermic
Types of reactions
- type of reaction?
polar reactions (2 reactants added up)
entropy goes down because two species become one
- what it does
- always forms?
- eliminate what?
always form alkenes
something from saturated/ neutral molecule to form pi bond
competes with elimination reaction
substitutes an atom with another
- polar vs nonpolar
Polar Substitution reactions
nucleophile and electrophile
very polar solvent needed
has anions and cations as intermediates
Nonpolar substitution reactions
intermediates not charged
__ need light/ energy.
Sometimes, over an arrow, what do you see?
you see conditions
All reactions need what?
no adding, subtracting, or substituting
rearrange electrons or atoms in a reaction
study of energy changes
What do we want to do?
What controls the reaction?
What is the deal with the above answer?
drive equilibrium products to completion
if you can't get past it, reaction doesn't occur
describes kinetics of reaction
if dependent on one reagent= first order
two= 2nd order
Bond breaking: nonpolar
sigma bonds break
one electron goes with each atom (fishhook demonstrates this)
results in free radicals
Bond breaking: polar
both electrons go to one species, usually the more electronegative
If you can break bonds, __ all bond sforming must be __ as well.
SImilarly, all __ must form __ as well.
: A⋅ + ⋅B --> A:B
: A+ + :B- --> A:B
Nonpolar reactions involve __.
How can we quickstart a reaction?
introduce a radical, allowing the A:B to break
doesn't occur in dark room
most effect wavelength= blue light
high quantum ueild
: making molecuels of products with single photon of light
When doing chlorination, how much Cl2 do we want to break?
not all of them; just a little bit
Forming a new radical creates a __
Radicals are used as __.
beginning of the next step
Eventually, you'll run out of energy. What happens?
free radicals find each other--> termination
When does termination occur?
if you don't propagate another radical
Explain bond dissociation energy?
to break bonds, you put energy in (+)
to form bonds, you get it back (-)