• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Ask me for chemistry help! (3 Viewers)

D

Dylanamali

Active Member
Joined
Jul 7, 2009
Messages
1,248
Gender
Male
HSC
2011
MagnificentOne said:
What is Le chatelier's principle?
Click to expand...
Applies to reversible reactions - states that if a system at equilibrium is disturbed, the system will shift in order to minimise the disturbane and obtain a new point of equilibrium.
 
D

Dylanamali

Active Member
Joined
Jul 7, 2009
Messages
1,248
Gender
Male
HSC
2011
kittyful said:
Why do we reflux ?
Click to expand...
Refluxing is the process done is esterification. Esterification is naturally a very slow process (the reaction between a alkanol and an alkanoic acid). Because of this we need heat, however both of the reactants are volatile and thus heating under an open system would cause a loss of reactants due to evaporation - however heating in a closed system will cause a build up in pressure, possibly resulting in explosions and the like - because of this we use a process known as refluxing which is basically attaching a condenser which condenses the reactants as they evaporate, minimising the loss of reactants, but still enabling the heating to speed up the reaction. The reaction is also sped up through the use of a conc. sulfuric acid catalyst which acts as both a catalyst as well as a dehydrating agent by absorbing the product of water and thus increasing the yield of the ester.
 
Y

yew

Member
Joined
Sep 11, 2010
Messages
39
Gender
Male
HSC
2011
Refluxing is done to allow for high temperatures, the reactants may condensate, but will drip back down ??
 
M

MagnificentOne

^_^
Joined
Apr 5, 2011
Messages
165
Location
I'm right here guys
Gender
Female
HSC
2011
Dylanamali said:
Refluxing is the process done is esterification. Esterification is naturally a very slow process (the reaction between a alkanol and an alkanoic acid). Because of this we need heat, however both of the reactants are volatile and thus heating under an open system would cause a loss of reactants due to evaporation - however heating in a closed system will cause a build up in pressure, possibly resulting in explosions and the like - because of this we use a process known as refluxing which is basically attaching a condenser which condenses the reactants as they evaporate, minimising the loss of reactants, but still enabling the heating to speed up the reaction. The reaction is also sped up through the use of a conc. sulfuric acid catalyst which acts as both a catalyst as well as a dehydrating agent by absorbing the product of water and thus increasing the yield of the ester.
Click to expand...
Splended!
 
You must log in or register to reply here.

Users Who Are Viewing This Thread (Users: 0, Guests: 3)

Top