Lead salts for 'Dragons breath' demo?

Discussion in 'Supporting Chemistry' started by Techitude, Feb 13, 2018.

  1. We do the Dragons Breath demo of metal salts in ethanol in a spray bottle that you spray over the bunsen flame to produce the flame test colours.

    I normally use copper, lithium, potassium and sodium salts to get the colours but a teacher has asked for a lead salt, stating "I've had it before" but I'm not 100% happy giving out lead for him to vaporise!

    Does anyone else use lead salts in their flame tests and is it safe (I have checked Cleapss that suggests no but it isnt specific to this use)
  2. For me its a straight no but then again they will have prepared a risk assessment for the procedure? :p
  3. I am going to say no but had to appear slightly receptive to the idea when originally asked as it was the HODwho wanted it ;)
  4. Lead only gives a greyish white colour anyway which is dull compared with others like strontium, barium and calcium which are other alternatives to offer and give showy colours,as well as the normal copper, potassium etc.
  5. Just what I was going to say - it's not particularly impressive. Really not worth the risk.
  6. He wanted it specifically to show the white colour, said he had done it before but he has graciously accepted my new rules of 'no lead dragons breath' irrespective of what the previous techs used to give him.
  7. I try and keep the kids away from as many toxic chemicals as possible. I would be very unhappy at vaporising lead salts into the air. There are specific regulations for working with lead and I would have a look at these. If one of my lot asked for that - (I doubt they would dare!) I would just laugh and say no way.
  8. This sounds great, do you have a practical sheet for this... minus the lead!
  9. This is the practical for testing for positive ions from the KS4 AQA syllabus I also used to dissolve the chlorides in ethanol and water and put them into small spray bottles for a demo. That was popular on open evenings. :)

    Attached Files:

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  10. Here are the instructions from the Nuffield Foundation and the Royal Society of Chemistry for this flame colour demonstration – I've not heard it called Dragon's Breath before, but I can see why it is!
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  11. Dragon's Breath usually refers to glucose/lycopodium powder blown through a bunsen flame.

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  12. We call that the custard powder flame thrower!