What observable evidence indicates that a chemical reaction is taking place?Ģ. In addition to ZnS( s ) some ZnO( s ) and some SO 2( g ) are produced by the high temperature of the second reaction.ĭemonstration Notes, Warnings, Safety Information, etc.ġ. Only when heated to the temperature of a red-hot metal rod do they react rapidly-in the case of zinc, almost explosively.Įquations for the principal reaction in each case are However, iron and sulfur and zinc and sulfur can be mixed at room temperature and no reaction takes place. Iron(II) sulfide and zinc sulfide are quite stable compounds and their formation from the metal and sulfur is highly exothermic. A heated metal rod causes the mixture to react vigorously. Zinc Play movie(QuickTime 3.0 Sorenson, duration 19 seconds, size 1.3 MB) The heat initiates an exothermic reaction. The reaction product, iron sulfide, is fused to the rod. A heated metal rod initiates an exothermic reaction. Iron Play movie(QuickTime 3.0 Sorenson, duration 32 seconds, size 2.2 MB) The reaction with zinc produces flame and a near explosion.Ĭombination reaction, descriptive chemistry, enthalpy/heat, evidence of chemical reaction, exothermic process, iron, metals, reactivity - kinetic/thermodynamic stability, redox reaction, sulfur/sulfur oxides/sulfuric acid When heated with a red-hot metal rod, mixtures of iron and sulfur and of zinc and sulfur react vigorously. Reactions of Iron with Sulfur, Zinc with Sulfur Reactions of Iron with Sulfur, Zinc with Sulfur