how would you test for O2 and CO2 gas?

Question

how would you test for O2 and CO2 gas? (what type of reaction would prove its existence?)

Answer 1

To test for O2:
Place a glowing splint in a test tube of oxygen. The splint is re-lit.

To test for CO2:
CO2 turns limewater milky.

Answer 2

If the O2 is confined in a cyliner or tube, I would fill the bowl of a deflagrating spoon with sulfur. Or, I would light a wooden splint on fire, thenm blow it out until there was just a glowing end of it. Then I would eithewr light the sulfur in the deflagrating spoon and plunge it into the cylinder, or I would plunge the glowing splint into the cylinder. In either case, with O2, I would expect a whoosh of combustion as the sulfur or the wood ignited. C + O2 ===> CO2; S + O2 ===> SO2.

I would shake up the confined CO2 gas with a solution of lime water [Ca(OH)2)]. The lime water is water-white. CO2 would cause it to turn milky in color. Ca(OH)2 + CO2 ===> CaCO3 + H2O

Answer 3

A combustion reaction would either prove or disprove the presence of oxygen. If you light a match and oxygen is present, the match will continue to burn. If you do the same thing and only carbon dioxide is present, the flame will go out almost immediately. I don't know if this is the answer you're looking for, but it's the way I would test for it.