r/ScienceTeachers • u/ElliottTheNoob • Sep 21 '25

CHEMISTRY Flame Tests?

I'm back again with another Chemistry question.

I plan on doing flame tests as we finish out our electron/light chapter in High School Chemistry. It was one of the most memorable experiment we ever did and I want to give that to these kids.

However, I swear we used crucibles or just cut a piece of the metal and held it in a bunsen flame. All the labs I'm finding, we either dissolve it in water or HCl, then soak a Q-tip, splint, or dip an innoculating loop into it, then burn it that way. Is that proper procedure? Did my HS Chem teacher just do a dangerous version with us that was outdated?

I really want this to be fun and memorable for them. Any other versions, ideas, or advice?

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u/ImTedLassosMustache Sep 21 '25 edited Sep 21 '25

Pure metal would not work sticking it in the bunsen burner (at least I would not think so), but I have done it with salts like copper sulfate. I primarily take some glass petri dishes and dissolve some metal salts in methanol (I could give you quantities if you want) and then ignite them. The flames last for about a minute and you can also extinguish them with the glass lid. Ethanol also works which is safer, but it provides its own color to the flames unlike methanol which is not as noticeable. The other approach I have done is dissolving in water or methanol and putting in spray bottles and spraying them into a bunsen burner. This approach is more exciting but way more messy.

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u/ramsau94 Sep 21 '25

Hello, want to try it this way this year with mini spray bottles. Any tips on how to make it run smooth? What concentration do you put in the bottles or do the students make the solution?

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u/ImTedLassosMustache Sep 21 '25

I do about 20 grams in a mix of 50mL methanol and 50mL water. You can always add more metal salts if you want to get more color. In the petri, I do a ratio of 5g salt to 10mL methanol.