Burnt coke in flask

Discussion in 'Supporting Chemistry' started by Jane9, Sep 12, 2019.

  1. Hi all, new technician here and very much still finding my feet!

    I've had a conical flask returned to me with burnt coke in the bottom following a distillation. Any recommendations of how I can clean this up nicely?

    Thanks :)
  2. Oh dear Jane, burnt Coke in Distillation Flask? Well this is actually a common problem when students have the temperature too high and heat to dryness. I usually add some Conc. Nitric Acid (good for all organics) to the Flask then leave it to stand overnight. Usually I'm left with a completely cleaned Flask. Job done!:D
    Jane9 likes this.
  3. Thanks George! Knew there would be something simple but thought I'd better check before I try something :D
  4. I find strong alkali works best on burnt on organics - 2M or above NaOH and soak overnight.