Two closed cylinders without labels contain carbon monoxide (IV) and hydrogen. Gases can be distinguished

Two closed cylinders without labels contain carbon monoxide (IV) and hydrogen. Gases can be distinguished 1) by color 2) by smell 3) using a burning torch 4) using filter paper moistened with an alcoholic solution of phenolphthalein.

Gases can be distinguished with a smoldering torch. Carbon dioxide does not support combustion, so a torch placed in a test tube with it will go out.

In a test tube with hydrogen, a flash will occur as a result of the combustion of hydrogen. The equation of the proceeding reaction:

2H2 + O2 = 2H2O