Melting point block

Discussion in 'Science Technicians - General Discussion' started by Hands Solo, Jul 5, 2018.

  1. Can anyone explain how to use one of these please. I've never seen one before and the chemistry teacher hasn't either.


    melting point block.jpg

    Thank you.
     
  2. Side arm held by clamp.
    Thermometer into large hole.
    Capilary tubing into smaller holes (samples being tested)
    Large opening is viewing area.
    Opposite end to thermometer is placed onto heat pad.

    Hope this helps
     
  3. ...or heated with a Bunsen burner.
     
  4. Spot of liquid paraffin in the thermometer hole to assist heat transfer. You could do the same thing with one of those specific heat blocks.
     
  5. has anyone used these melting point blocks and if so are they worth buying
     
  6. It is - so it goes slowly and is more accurate. If you use a variable power supply for the setup, you can go even more slowly. I see that as an advantage, as students invariably try to do it too quickly and grossly overshoot.

    Another advantage is that you are likely to have a class set of these blocks, so everyone gets a go. Unless you go hyper-expensive (rather than just super or ultra) melting point apparati take ages to cool down so you get very limited opportunity in a lesson.
     
  7. Thanks for the replies folks.

    Sorry for the delay in replying, was lucky enough to go away for a short break over the weekend.

    We have 10 of these and, as we are a small school, this should be plenty for our 6th form. Sadly no nice heating pads to go with them so we'll have to use bunsen burners.
     
  8. Where did you get yours from?
     
  9. how many schools have the electric apparatus, we have been fortunate to acquire 3 sets but I'm amazed how much it would cost new.
     
  10. We used to (probably bought in lmid '80s) have a couple of the Gallenkamp digital Melting point apparatus, but they both eventually ceased to work. They were a pain to fix when students broke the melting point tubes off in them.

    We have a couple of the Philip Harris ones, but we don't tend to use them, as with classes of about a dozen, too many students crowd around at once.

    We use the Edulab aluminium melting point blocks now - http://www.edulab.com/prod/melting-point-block
     
  11. we have one stuart and two gallenkamp. All using a standard 300 deg thermometer. Each can hold three capillaries but we would prefer one per group. They work in small teams to make aspirin so four apparatus would be ideal at the moment. If anybody has any spare that need a home speak up!