Hey! Sign in to get help with your study questionsNew here? Join for free to post

HELP - equilibrium constant calculations for esterification

Announcements Posted on
AQA GCSE physics P1 unofficial mark scheme 05-05-2016
  1. Offline

    Just come back to my chemistry coursework after revision and holidays. Does anyone know if you have to take into consideration the water used to dilute the reactants in an equilibrium reaction when you are calculating the equilibrium constant? If so, how?!
    I'm reacting short chained alcohols and carboxylic acids to produce esters and water.

    Please, someone, help??
  2. Offline

    You probably don't need to take into account of water because its dissociation constant is very very small.
  3. Online

    no, for esterification you DO need to consider the concentration of the water in the mixture.
    It does take part in the equilibrium.
  4. Offline

    i thought as much, any help on how to do it though?

  5. Online

    how to do what? the whole experiment?
  6. Offline

    nope, done the experiment and calculated how much acid was left at the end of the experiment and therefore how much ester was producted. However I need to calculate Kc and i dont know how to take the extra water into account when i'm doing that.
  7. Online

    you already have the mass of the water you started with from the mass of the HCl solution (or whatever other acid) you added. (subtract the mass of HCl contained)
    The extra moles of water will be equal to the moles of acid used up in the esterification.

    I am assuming that you titrated the mixture both before and after the equilibrium was established to find the total moles of acid present (= moles of acid catalyst + moles of ethanoic acid)
  8. Offline

    Thanks . Have attempted to sort it out but going to my chem teacher tomorrow and getting it checked.



Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: January 21, 2007
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR

AQA physics unit 1

Check the unofficial mark scheme

What date is the EU referendum on?
Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.