Turn on thread page Beta
    • Thread Starter
    Offline

    14
    ReputationRep:
    Hi everyone, I am currently revising for my chemistry mock and I came across this question. Can you please help and explain how you would answer the question?

    Your help will be appreciated
    Name:  Capture.PNG
Views: 40
Size:  21.0 KB
    • Community Assistant
    • Study Helper
    Offline

    17
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by starstudent7)
    Hi everyone, I am currently revising for my chemistry mock and I came across this question. Can you please help and explain how you would approach the question. I have also attached the answer from the mark scheme.

    Your help will be appreciated.
    I would approach carefully avoiding eye contact ...
    Offline

    9
    ReputationRep:
    (Original post by starstudent7)
    Hi everyone, I am currently revising for my chemistry mock and I came across this question. Can you please help and explain how you would answer the question?

    Your help will be appreciated
    Did you forget the attachment? Easily done.
    Offline

    17
    ReputationRep:
    (Original post by starstudent7)
    Attachment 717186Hi everyone, I am currently revising for my chemistry mock and I came across this question. Can you please help and explain how you would answer the question?

    Your help will be appreciated
    Its pretty damn difficult to answer your question without knowing what it is.
    Posted on the TSR App. Download from Apple or Google Play
    • Thread Starter
    Offline

    14
    ReputationRep:
    (Original post by TutorsChemistry)
    Did you forget the attachment? Easily done.
    I have attached now thank you
    Offline

    9
    ReputationRep:
    (Original post by starstudent7)
    Hi everyone, I am currently revising for my chemistry mock and I came across this question. Can you please help and explain how you would answer the question?

    Your help will be appreciated
    Name:  Capture.PNG
Views: 40
Size:  21.0 KB
    When you make biodiesel you are trans-esterifying the 1 mole of triglyceride into 3 moles of methyl esters.

    The triglyceride on the left can be thought of as an ester of 3 fatty acids with glycerol (because that's what it is). The image may help visualise it.


    The reaction replaces the gycerol with the CH3O- of methanol.

    So you will need to add methanol - I will let you decide how many moles you think are needed to balance.

    And if glycerol is being replaced, that must be the missing product.
    (The products shown in the question are the methyl esters of the fatty acids in the triglyceride).

    I know your question doesn't ask... but any thoughts on the conditions for this reaction?
    • Thread Starter
    Offline

    14
    ReputationRep:
    (Original post by TutorsChemistry)
    When you make biodiesel you are trans-esterifying the 1 mole of triglyceride into 3 moles of methyl esters.

    The triglyceride on the left can be thought of as an ester of 3 fatty acids with glycerol (because that's what it is). The image may help visualise it.


    The reaction replaces the gycerol with the CH3O- of methanol.

    So you will need to add methanol - I will let you decide how many moles you think are needed to balance.

    And if glycerol is being replaced, that must be the missing product.
    (The products shown in the question are the methyl esters of the fatty acids in the triglyceride).

    I know your question doesn't ask... but any thoughts on the conditions for this reaction?
    Thank you so much for your help. I realised that I wasn't looking at the question properly and that it was straightforward. The conditions of the reaction are: KOH catalyst, alcohol, reflux
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: January 9, 2018

University open days

  • University of Bradford
    All faculties Undergraduate
    Wed, 21 Nov '18
  • Buckinghamshire New University
    All Faculties Postgraduate
    Wed, 21 Nov '18
  • Heriot-Watt University
    All Schools Postgraduate
    Wed, 21 Nov '18
Poll
Black Friday: Yay or Nay?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.