Flame Test

[macca]

Hi Brains Trust

We normally do flame test with Yr9 +, question is I have a teacher wishing to do with Yr7.
Do you do with year 7s?
Do you do a simplified version if so what chemicals eg., Sodium Chloride.

I can't even see what topic she would be relating too, unless she is jumping ahead to states of matter!

[Merilyn1]

Oh why?? Agree, not normally a prac that anyone would consider doing with Year 7. If the teacher insists, I'd be soaking paddle pop sticks in solution. Don't give them spray bottles
Better still a demonstration or a Youtube video!

[RosalieL]

Yeah, I'd be pointing out to the year 7 teacher that if they do it now, they won't want to do it in yr 9. Maybe a demonstration of two compounds to show there's a difference would be ok, but not the full "flame test" prac. Is she an approachable teacher? Can you find out what point she is wanting to make and suggest an alternative? Feel free to come back here for ideas!

[mtg]

We have done it as a forensic prac. Maybe for Yr 7 :- Elements? I think sometimes we have done it in yrs 7,8,9,10 and 11!!! I think we usually do it in yr 10. And then with spectroscopes etc as seniors. I usually go the toothpick dipped in water then salt then burnt. Demos might be best for yr 7 if it's a big group.

[Lyn]

I have just had a look through several different Y7 textbooks that we have here and none of them mention flame tests. What Y7 textbook are you using? Even Y7 states of matter practicals don't cover flame tests. If push comes to shove then paddle pop sticks soaked in solutions. Keep the pretty flame test solutions for later year levels.

[macca]

I have just had a look through several different Y7 textbooks that we have here and none of them mention flame tests. What Y7 textbook are you using? Even Y7 states of matter practicals don't cover flame tests. If push comes to shove then paddle pop sticks soaked in solutions. Keep the pretty flame test solutions for later year levels.

No it's not in ours either and they are still doing "The Solar System" new young teacher, I have a meeting with her. Will let you know the outcome.

[macca]

Thanks everyone,

Yeah wants to relate to solar system, but I've said no, she just wants to do a prac I think. So as a demo only, these kids are still having trouble lighting bunsens. They are never going to understand what, why or how to do the prac., but anyway. Teacher didn't want it referred to the HT so we have compromised with a demo.

[RosalieL]

Thanks everyone,

Yeah wants to relate to solar system, but I've said no, she just wants to do a prac I think. So as a demo only, these kids are still having trouble lighting bunsens. They are never going to understand what, why or how to do the prac., but anyway. Teacher didn't want it referred to the HT so we have compromised with a demo.

Good negotiating! She must know she doesn't really have a valid reason if she doesn't want the HT involved! I'm struggling to relate flame tests to the solar system though... different star colours? That's to do with heat not chemical composition though, isn't it? Anyway, good outcome if both the teacher and labbie are happy!

[RosalieL]

What's the list of chemicals you send out for flame tests?

[labbassistant]

All 1M
- Barium Chloride
- Calcium Chloride
- Copper Sulfate
- Lithium Carbonate
- Potassium Chloride
- Sodium Chloride
- Strontium Chloride

We have been asked for the powders but most of the time we give the solutions

[Anna Z]

same as above for us.

[labbassistant]

Hi all,
I was looking for info on flame tests and saw my above post which I said we use strontium chloride which is incorrect. We use strontium carbonate.
But my question is does anyone use strontium chloride? We have lots and have run out of strontium carbonate. Does it show the same colour?

[Anastasia]

The flame colour depends on the metal cation so strontium carbonate and strontium chloride should give the same result. We use strontium chloride and it works well.

[labbassistant]

Great, thanks so much!

[Kathryn]

We do flame test (paddle pop method) for the Yr 7 orientation. They have a bunch of older students in the class with them. They do 4 mystery chemicals which they have to work out what they are. We find it a great but simple prac to get them excited about doing science the next year.

[RosalieL]

Has anyone used copper oxide or copper hydroxide for a flame test? We've got a student wanting to do it as part of their investigation assessment. I can't see any reason not to stick them in a flame, but am I missing something obvious?

[bigmack]

Funny you mentioned that . Just yesterday I tried Copper Oxide as a possibility for an upcoming copper mining prac . It did nothing .Just a lump of orange glowing stuff on the end of an inoculation wand .

Actually , it was a bit if a pain to get off the wand . Sorry don’t have Copper Hydroxide . If you have some try it yourself .

But can’t see any dangers as such .

[RosalieL]

Thanks bigmack! I think all they will prove is that a bunsen doesn't provide enough heat to break the bonds.... I think what they are hoping to show is that copper is what provides the flame colour, not whatever it is bonded to.

[bucketchem]

perhaps they could compare the sulfate to the chloride? iva also not tried the hydroxide but i dont see any problem with it, as long as it's a solution and not a solid. probably wouldnt risk the solid

[Pm706Narrogin]

What method are we all using for the flame test?

We currently use the popstick method, soaking the sticks in solution overnight. One of our teachers saw the alternative way to do this by soaking the popstick in distilled water, dipping the stick in a little bit of the solid chemical and putting it in the flame. She tried that method with much more spectacular visual results.

We're considering changing to the second method (soaking in distilled water and dispensing a small amount of solid metal chloride in a beaker) for when the 10s do the flame test. Any pitfalls to be aware of? The Science ASSIST advice (linked) doesn't make a distinction between the popstick methods with regard to safety.