Turn on thread page Beta
    • Thread Starter
    Offline

    2
    ReputationRep:
    Calculate the amount ot Triethanol (Molecular weight = 149.19) required to make 500mls of a 200mM solution.

    I don't even know where to start!
    Offline

    11
    ReputationRep:
    (Original post by ChemEng90)
    Calculate the amount ot Triethanol (Molecular weight = 149.19) required to make 500mls of a 200mM solution.

    I don't even know where to start!
    mol of solid = mass in g / molar mass in g per mol

    mol of solutions = concentration in mol per dm cube x volume in dm cube

    Find mol of the solution you want to make, then equate with mol of solid, find the mass of solid required in g. Though I imagine, triethanol is probably liquid?
    • Thread Starter
    Offline

    2
    ReputationRep:
    ...Rep to anyone who can works this out. I'm baffled!!!
    Offline

    19
    Work out how many moles you need

    500 mL/0.5 dm3 and 200 x 10-3 mol dm-3

    concentration = moles/volume
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by EierVonSatan)
    Work out how many moles you need

    500 mL/0.5 dm3 and 200 mol dm-3

    concentration = moles/volume
    Rewrite the second line please, it's not clear mate. It's partly coming back to me now lol.
    Offline

    11
    ReputationRep:
    hmm, elementary chemist
    • Thread Starter
    Offline

    2
    ReputationRep:
    This isn't for me, it's for a friend lol. I don't do Chemistry, nor have time for it lol.
    Offline

    19
    I've been trying to edit that post for 15 minutes

    :lol: fixed
    • Thread Starter
    Offline

    2
    ReputationRep:
    ....scratch that LIE. Retardation and tiredness set in.
    • Thread Starter
    Offline

    2
    ReputationRep:
    Thanks EierVonSatan and shengoc. I'll rep you both.
    • Thread Starter
    Offline

    2
    ReputationRep:
    The term 'Molecular weight' threw me off completely, cos I'm used to seeing molecular mass.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: February 7, 2010

University open days

  1. University of Bradford
    University-wide Postgraduate
    Wed, 25 Jul '18
  2. University of Buckingham
    Psychology Taster Tutorial Undergraduate
    Wed, 25 Jul '18
  3. Bournemouth University
    Clearing Campus Visit Undergraduate
    Wed, 1 Aug '18
Poll
How are you feeling in the run-up to Results Day 2018?

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.