Search results

  1. T

    No wonder the students can't be bothered...

    We are about to do past papers as practical tests for both years of sixth form, titrations. The exam papers say to give them a pre-weighed amount, within a small range. Not recorded. Normally that is not done for the first years and they weigh out the amount themselves. Now to reduce mingling...
  2. T

    No wonder the students can't be bothered...

    I am worried that it will undervalue all their grades. The idea you didn't do a real exam so whatever grade you got, you didn't deserve. Disadvantages the ones who understand and know all the curriculum. And passes on the problem - what do they do at university, hopefully back to normal, when...
  3. T

    shelf supports for flammables cupboard

    I have an old flammables cupboard where the shelves rest on supports hooked into round holes on the vertical strips. I want some more shelf support angles (previous ones lost at some point) but the ones I have seen are the wrong type. The catalogues don't show the insides so I can't see who I...
  4. T

    rescuing wet chlorides

    thanks I dried it out as much as I could in the time, and slightly mushy lithium gave a lovely colour, and magnesium didn't do anything weird, so that is all good.
  5. T

    rescuing wet chlorides

    thanks Trouble is teacher wants solid and flame test wires. And logistically I can't make 10 sets of 6 ions each in sprays. They normally do it in a circus apparently but now they have to have everything for each student so they don't move about. I can give them semi-dried mush, not really a...
  6. T

    rescuing wet chlorides

    I have some ancient chlorides which have taken in water and turned mushy, and others that have dried out again into a solid block. As I understand these have merely dissolved, not reacted with the water, so heat drying them out should restore a usable chloride of lithium, magnesium. Am I right...
  7. T

    amino acids from powders

    I know this has probably been asked before but I can't find an answer - I have amino acid powders (1g vials from Timstar) - how do I make up solutions for paper chromatography?
  8. T

    disinfecting / quarantining dissection kit

    I know the reasons for using Milton because that is actively 'sterilising', but I am confused why you would want antibacterial washing up liquid. It is soap and water that kills virus so I can't see any anti-bacterial component adding more. I am genuinely curious, not having a dig. The whole...
  9. T

    long needles to fit syringes

    thanks now I will have to think of how to corner my local vet and ask for a long needle without looking like a psycho!
  10. T

    Your safe from COVID if your not in close prox. for more than 15 mins?

    Apparently to tell the app you have symptoms you have to enter the code for the positive test. It came up on a radio programme because that only works for out of hospital tests, as hospital tests are on a different system. But for contact advisories I don't know, There might be a code for that...
  11. T

    Your safe from COVID if your not in close prox. for more than 15 mins?

    slightly off topic, but I can understand the chin protection in kids - poor risk judgement, ideas of consequences for others and it is all a bit abstract. And they are no fun to wear. But the number of adults I see on public transport with them over their mouths but not their noses - I know more...
  12. T

    Your safe from COVID if your not in close prox. for more than 15 mins?

    We are sixth form college in 'medium risk' area, although cases are rising. Just moved to mandatory masks in corridors this week. Before that it was advised but most students weren't doing it (from what I could see - I am generally out of the way in my room and only emerge during lessons...
  13. T

    oxidised phenol

    I have some phenol which has gone a beautiful pink with scarlet highlights. Can it be saved (without anything too drastic like hydrogen gas)? - I would prefer not to have the hassle of disposal even for a small amount, but to be honest I am just curious anyway.
  14. T

    long needles to fit syringes

    I am looking for injecting needles that fit on the end of the standard plastic syringes (2/4/10ml). I want some 38mm long to stick through bungs for hydrogen peroxide practicals, and I think I have found these from Beecroft. http://www.beecroft-science.co.uk/view-product.php?id=3692 But I am...
  15. T

    How often to check autoclave?

    Remember the pressure is not the important part in the sterilisation - it is the temperature that is important. The pressure is just the steam being unable to escape and water being trapped as liquid because it is unable to access the space occupied by steam. So the strip just shows it has...
  16. T

    How often to check autoclave?

    yes, the strip tells you it has done the job of sterilisation the annual test tells you it won't fail under pressure and shower you with shrapnel and superheated steam. I know which one I care more about!
  17. T

    Phytoremediation

    ah, thanks.
  18. T

    Hazcards or Student Safety Sheets

    We have hazcards available in labs (couldn't guarantee they are the latest) but I am sure the teachers never refer to them. It would be a waste of time sending out hazcards to the teacher with practicals - they wouldn't look at them anyway. Any first aid is pretty clear anyway, and the...
  19. T

    Phytoremediation

    I am interested in how this is supposd to show anything. Are you testing soil or water before and after? Some indicator of contamination? Iwould have thought you have to give it time. Otherwise you are just watching some plants.
  20. T

    Room ventilation

    I am lucky to have a largish window with sash pull. It is over the sink, and I get enough breeze to be cold and blow papers around, although it is the other end of the long room from my computer. I once refused a job because of the layout of the prep room ( and because the incumbent senior...
Top