Sciencemadness Discussion Board

Candles for heating test tubes

Sulaiman - 30-8-2018 at 09:07

nIhno3_candle_wide.jpg - 2.2MB nIhno3_candle.jpg - 1.3MB

Nothing new, posted just because I thought I'd mention/remind the use of candles for heating test tubes.
My spirit lamp recently died but I wanted to make a little nickel nitrate,
IKEA GLIMMA candles to the rescue.
0.3g nickel, 10ml 1M HNO3, 1.4ml 10% H2O2 in a 20ml soda-lime glass test tube,
... boil, simmer or keep hot depending on gap between test tube and flame.
4 hours per £0.025 candle.

Useful for daily use and especially for 'emergency' use.

Not sure if the nickel will 'dissolve' but the candle works well :P

fusso - 30-8-2018 at 12:03

Why is the solution yellow not green?

Ubya - 30-8-2018 at 12:25

those are some cheap candles:o

Morgan - 30-8-2018 at 13:02

Quote: Originally posted by Ubya  
those are some cheap candles:o


That was a funny comment.
Another heat source made from a tealight candle ...
https://youtube.com/watch?v=HxsJna3tMF4

[Edited on 30-8-2018 by Morgan]

unionised - 30-8-2018 at 13:06

The big problem is soot.

Ubya - 30-8-2018 at 13:22

Quote: Originally posted by unionised  
The big problem is soot.


the problem would be real with a flame producing a column of black soot but if the wick is well made and you keep the test tube outside the flame cone of the candle it shouldn't be a problem

Sulaiman - 30-8-2018 at 14:29

These candles seem to be smokeless so as above ... no soot.



...............................................................
The yellow/orange is dissolved NO2 caused by earlier boiling,
there is no green because a negligible quantity of nickel has dissolved :(
(if no change by tomorrow I'll ruin the stoichiometry and add some rfna) :o

unionised - 31-8-2018 at 01:03

Candles must have improved since I was a schoolkid. (Meths was too expensive).

I did try using what would now be called and "air bath"- a small tin can heated in the flame. The can got sooty, but the tube inside stayed clean.