<P> A burning splint can be used to test for a combustible gas . A sample of the gas is trapped in a vessel such as a boiling tube with a stopper . A splint is lit and held near the opening of the tube, then the stopper is removed to expose the splint to the gas . </P> <P> If the gas is flammable, the mixture ignites . This test is most commonly used to identify hydrogen, which ignites with a distinctive' squeaky pop' sound . Hydrogen is easily ignited, as it is flammable over a wide range of concentrations in air, making this test quite robust . If the gas is non-flammable, the burning splint will be extinguished . As many other common gases are not flammable (such as carbon dioxide, nitrogen, and argon, etc .), this test cannot be used to definitively conclude what the gas actually is . Further analytical chemistry techniques can clarify the identity of the gas in question . </P> <P> The glowing splint test is a test for an oxidising gas, such as oxygen . In this test, a splint is lit, allowed to burn for a few seconds, then blown out by mouth or by shaking . Whilst the ember at the tip is still glowing hot, the splint is introduced to the gas sample that has been trapped in a vessel . </P> <P> Upon exposure to concentrated oxygen gas, the glowing ember flares, and re-ignites to produce a sustained flame . The more concentrated the oxygen, the faster the wood burns, and the more intense the flame . This test is not specific for oxygen, but will react similarly for any oxidising gas (such as nitrous oxide) that supports the combustion of the splint . </P>

How could we test for the presence of oxygen in this decomposition reaction