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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: kenhung123 on August 22, 2010, 11:50:10 am

Title: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: kenhung123 on August 22, 2010, 11:50:10 am

Is this reaction exo or endo?

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: 98.40_for_sure on August 22, 2010, 12:19:46 pm

As far as i know, this reaction is a simple dilution and no energy is produced or absorbed. And i can't find an enthalpy value for it anywhere, so it's neither exo nor endo

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: kenhung123 on August 22, 2010, 12:39:42 pm

Yea but SO3+H2O=H2SO4 is also dilution and is exo though

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: happyhappyland on August 22, 2010, 12:46:52 pm

its exothermic.

Its not a dilution.

SO3 + H2O = H2SO4 releases too much energy thus the sulfuric acid forms into a mist which is too hard to collect therefore we split this equation in to 2 and effectively you split the energy released. Lets call energy released here amount "C"

So we put it into two equations the first being
SO3 + H2SO4= H2S2O7 ENERGY IS RELEASED but less than "C" so lets call it "A"

Then
H2S2O7 + H2O = 2H2SO4 energy again is released but ALSO less than "C" so no mist of h2so4 is formed Call energy released "B"

A + B must = C. but by splitting up the equation you allow less heat generated in such short amount of time.

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: kenhung123 on August 22, 2010, 12:55:42 pm

Wow that was very intelligent of you to figure that out. Thanks.
Is the chamber which H2S2O7+H2O not called the diluter?

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: superflya on August 22, 2010, 01:21:44 pm

dilution tower?? the oleum is simply hydrated to produce sulfuric acid, dont know where u got dilution tower from :/

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: kenhung123 on August 22, 2010, 01:41:48 pm

Ok thanks

Title: Re: Enthalpy H2S2O7+H2O=>2H2SO4
Post by: akira88 on August 23, 2010, 04:48:43 pm

Yeah it is called the diluter.