Science Buddies: "Ask an Expert"

please help me, i need to know how can i burn copper, lead and iron. i tried it solid form it did not work. my project is, can we identify different metal by the color of the flame. please help

Hi Romeo,

Could you tell me what you tried to burn the metals with. Also, you want to be very careful when you burn those because some of the metals will release toxic fumes and could be harmful.

Good luck,
Philip

Hi Philip,

I tried to burn with the torch and also i tried with candle which obviously didn't work. any suggestion, please reply.


Thanks,

R

Hi Romeo,

I would recommend using a bunsen burner to melt your metals. The candle and torch(not a welding torch) are not hot enough to melt the metals because the gas and air mixture is not good.

A bunsen burner lets you change the gas and oxygen that mixes together to make it hotter. If you set it up right, you will only see a blue flame which is very, very hot and will melt your metals. However, you have to be more careful working with a bunsen burner. You might check with your teacher and see if they could let you use one.

Also, before you work with lead, which I don't recommend, please make sure that you understand the safety precautions because it can be dangerous.

Please let us know how it goes.

Philip

I suspect it is not the blue part of the flame you want. While hot, it is a "reducing" flame, which is the opposite of oxidizing (you should research this). The yellow part of the flame will oxidize the metal and perhaps display the emission spectra you are looking for.

Try placing small samples of metal on a stone or concrete surface (be safe!) and try burning with different parts of the flame from a blowtorch or gas-fueled bunsen burner as suggested above.

And yes, the visible color of the metal's emission spectrum is different for different metals. Metal salts produce the varying colors of fireworks.

Also, the metal may not need to be in its metallic form. You may want to try some common salts of the metals and see if it is easier to get the spectra.

WARNING! this may produce toxic fumes, and there is the risk of the flame blowing hot debris to inappropriate places. Do this in a functioning fume hood with the ventilator on, or in a very well-ventilated area where you will not be able to breathe any of the fumes produced in the process or come in contact with hot debris.