March 15 2012 5 15 /03 /March /2012 15:01
Titanium, as a left side transition metal, is more prone to vigorous reactions at high temperatures than at low (e.g. room) temperatures. Actually, at low temperatures, titanium is an inert metal, hardly dissolving in or reacting with any acid, base, or chemical.
When copper(II) chloride crystals are placed on titanium and then heated, the blue-green copper(II) chloride dihydrate is first dehydrated to the brown anhydrous form. Then the excess HCl present in my copper(II) chloride is released and the CuCl2 begins heating. A blue flame color is observed, as well as some sparks. When the titanium gets hot enough, however, a red-orange flame shoots out of the titanium metal, and a cloud of white smoke is released. No copper(II) chloride remains after this reaction, but copper metal does, and underneath the black copper(II) oxide surface lies reddish-brown copper metal. A significant portion of the titanium reacted with the copper chloride, making the resulting titanium piece thin and brittle. What reactions occurred here? It seems that 2 CuCl2 + Ti + 2 H2O (from atmosphere) --> TiO2 (smoke) + 2 Cu + 4 HCl is a potential reaction. This is a net reaction, taking into account the instant hydrolysis of titanium tetrachloride in moist air. Unfortunately, the camera overexposed during the video, so much of the flame looks white instead of the wide range of colors that actually existed.
If titanium tetrachloride is really formed, then doing this reaction in a closed crucible may produce some of the volatile substance without hydrolysis.