Barking dog reaction

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The barking dog reaction is an exothermic chemical reaction that results from the ignition of a mixture of carbon disulfide and nitrous oxide in a cylindrical tube, like a graduated cylinder.[1] When ignited, the reaction produces a bright flash and a loud "woof"-like sound, reminiscent of a barking dog.

Mechanism

In simple terms, the "barking dog" reaction is a combustion process, in which a fuel (carbon disulfide, CS2) reacts with an oxidizing agent (nitrous oxide, N2O), producing heat and elemental sulfur. The flame front in the reaction is a zone of very hot, luminous gas, produced by the reactants decomposing:

8 N2O + 4 CS2 → S8 + 4 CO2 + 8 N2

The length of the tube causes the sound of the reaction.

Video demonstrations

References

  1. http://jchemed.chem.wisc.edu/Journal/Issues/2006/May/abs751.html%7Cdoi=10.1021/ed083p751

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