Organic Chemistry

Butane Burner Explorations

·      The butane burner had a small air inlet above the shield.

·       As the air inlet was opened, the flame turned bright blue.  When it was closed again, the flame returned to yellow.

·      When the watch glass was held over the yellow flame, smoke began to come around the sides of the watch glass, bringing the smell of the butane.  A black deposit started to form on the surface.  This deposit felt very chalky and came of the watch glass very easily.

·      The watch glass was held over the blue flame.  There was almost no smoke, yet it smelled very strongly of the butane gas.  The watch glass did not blacken, but there seemed to be condensation on it.

·      When the burner was lit with the match on it, the flame immediately sparked intense white sparks.  After about 2 seconds, the match ignited, but afterwards, one couldn’t see the burning match. When the burner was turned off, the match stayed lit.  It then turned a glowing red and went out.

·      When the copper wire was inserted into cone C, the flame turned red and the wire glowed bright red.

·      When the copper wire was inserted into cone B, the top half of the flame turned red and the wire glowed once more.

·      When the copper wire was inserted into cone A, there was a tint of pink on the wire.


Discussion

            To turn the butane burner on, the air inlet must be closed. This produces a yellow flame.  Butane is a fossil fuel and is made up of carbon and hydrogen.  The chemical formula for butane is C4H10. When butane is burned, oxygen is added.  Because there is carbon in butane, it can be assumed that the black deposit on the watch glass was carbon. When the oxygen combined with the carbon, carbon dioxide (CO2) was created.  The reason condensation was seen on the glass over the blue flame was because the hydrogen combined with the oxygen to make water (H2O). The yellow flame also emitted water, but it was hard to see because of the carbon deposit.

            The reason the match didn’t burn while the flame was on is because it was in cone A. Cone A seems to be hollow. It is a space where only gas (in this case butane) and nothing else is. The reason there is no flame in cone A is that no oxygen is available to it.  The hottest part of the flame is cone B because there is the most gas in the flame without being pure gas.  This is why the wire glowed so vibrantly in cone B.