B. Iodine liquor is an alcoholic solution of iodine, in which iodine is a solute and alcohol is a solvent; So the narrative is correct;
C, when making a cake, some baking soda is decomposed by heat to produce carbon dioxide gas, which makes the cake loose and porous, so the description is correct;
D. The content of heavy metal chromium in "industrial gelatin made of worn leather shoes" is seriously exceeding the standard, and taking such capsules will do harm to human body, so the description is wrong.
So choose: D.