Specific heat capacity for year 11 with mercuary thermometers

Discussion in 'Supporting Physics' started by Jburns, Oct 11, 2019 at 8:16 AM.

  1. Hey guys,

    I have a physics teacher that wants to do this with year 11 but using mercuary thermometers, I have said no to this as she can use alcohol thermometers. So she is throwing toys out of the pram saying she is going to cancel the core prac as it does not work with alcohol thermometers, have you guys got it to work with them?

    The hazcard says (Y12) but she says as the kids only read them that this is allowed.

    What does the hive mind say in this situation? I say no and she can cancel the practical!
     
  2. karen b

    karen b COMMITTEE

    Not sure what practical you are doing, but we have definitely done one using immersion heaters and blocks of copper, steel, etc. using alcohol thermometers and got reasonable results.

    There is little difference in the accuracy of alcohol versus mercury thermometers in the school setting. A Chemistry teacher here, who was previously a research chemist, is happy for them to be used even at sixth form level
     
  3. _Good quality_ alcohol/oil thermometers can be close to mercury in accuracy. Maybe the answer is for the students to suggest ways of improving the experiment in their writeup? Which should, of course, happen anyway....
     
  4. According to her, why doesn't it work with alcohol thermometers? What's her reasoning?
    We use them and it works fine

    If she's claiming not to get the resolution for the temp change with alcohol ones tell her all they need to do is run it for longer...... time is one of the variables in the equation so as long as they know what time they measured over then it doesn't matter if it's 1 second or 15 hours.......
     
  5. We do the Steel blocks with alcohol thermometers.
    No one has complained yet.
     
  6. is it calibrated to an NPL one, if not it makes no difference, how do you know which is correct?

    We use alcohol ones with 6th form.
     

  7. We only use alcohol thermometers. Have done this practical this week with 6th form and have never had problems by not using mercury. I certainly wouldn't put mercury out for year 11. Big fuss over nothing as is usual with teachers :D
     
  8. Nick Mitchener

    Nick Mitchener COMMITTEE

    Absolutely no problems with alcohol thermometers, we use them for everything. Tell them they are not available. I don't think we use mercury ones at all now, Chemistry had some but they use alcohol for melting point of aspirin too, they are 300mm long.
     
  9. That's what she is claiming. I will let her know that alcohol ones are viable for this it just takes longer.

    That's the one they are doing.

    We just get the coloured alcohol ones from sci-chem/breckland/SLS sell.

    I didn't know the National Polo League calibrated thermometers


    Thanks for all the advice guys. I will let her know she has the choice of Alcohol thermometers or no thermometers.
     
  10. NPL = National Physical Laboratory - They went digital years ago, broke a few GBP 100 mercury thermometers in my time.
     
  11. For me it isn't my call - the teacher is responsible for H&S - you give her appropriate advice (and document it) then give her what she wants.
    Why beat yourself up about it and/or fall out with teachers - no need at all.
     
  12. because you end up dealing with the spillage and cleanup.
     
    Nick Mitchener likes this.
  13. For me its more I have been blamed before for teachers going wrong in the labs so I limit risk of back lash even though I know its not my issue. Plus she is being a major pain at the moment and not ordering practicals how she should do.

    Looks like the issue for the practical is the thermometers are too quick to read. So I am guessing lower voltage through the heater would solve this?


    This too!
     
  14. and I though you were doing it for the safety of the students:rolleyes:
     
  15. Seems there's a bigger picture here - not just the thermometers
     
  16. There is a bigger picture here but she has issues with the thermometers with this practical so I am trying to find a solution.

    Any helpful ideas?
     
  17. Can you go to your HoD for a ruling, maybe with a reminder of the consequences of going against CLEAPSS advice should an accident occur? To be honest, whilst we always do our best to advise on safety, the final call has to be made by the teacher unless overruled by the HoD. Make sure that you note in writing the advice that you have given, just to cover your own back if something goes wrong.
     
    Peter Sigsworth likes this.
  18. Nick Mitchener

    Nick Mitchener COMMITTEE

    We use 5 minutes max with metal blocks as we have 50 watt heaters which will get the copper up to far too high a temp over the ten mins suggested by AQA. Five readings, one a minute, it isn't really too complicated.

    Water takes longer, but same kit. You can use a kettle as a demo for water, really simple and much quicker
     
  19. This ;)
    At the end of the day you can offer expertise and advice Jburns but the long and the short of it is the buck for Science H&S stops with the HoD, if they're happy to allow it and the teacher is willing to risk assess it then it's gonna happen
     
    Peter Sigsworth likes this.
  20. I'm with a couple of the others.

    If I say no and they throw their teddies out the pram then I tell them to go to the HOD who is welcome to override me. Make a note on lablogger in the risk assessment section add a spills kit to the order and move on.

    Not paid enough for that nonsense.