Sparks or certain radiations can cause a mixture of hydrogen and chlorine to react explosively to yield hydrogen chloride, as represented by the equation H2 + Cl2 → 2HCl. Mixtures of hydrogen and oxygen react at a measurable rate only above 300° C, according to the equation 2H2 + O2 → 2H2O. Such mixtures containing 4 to 94 percent hydrogen ignite when heated to 550°–600° C or when brought into contact with a catalyst, spark, or flame.
The explosion of a 2:1 mixture of hydrogen and oxygen is especially violent. Almost all metals and nonmetals react with hydrogen at high temperatures. At elevated temperatures and pressures hydrogen reduces the oxides of most metals and many metallic salts to the metals. For example, hydrogen gas and ferrous oxide react, yielding metallic iron and water, H2 + FeO → Fe + H2O; hydrogen gas reduces palladium chloride to form palladium metal and hydrogen chloride, H2 + PdCl2 → Pd + 2HCl.
The age of H2 is here.
Still with caution.
Keep up good work!