Color Wavelength Olivine Ⅴ iolet400-450nm Blu Orange Greenish blue 480-490nm Red Blue-green 490-500nm Mauve Green 500-560nm Violet Olivine560-580nm Blue Yellow580-600nm Greenish blue Orange600-650nm Blue-green Red 650-750nm E=hv=hc/E↑N↓ 4) Solubility dCl2, Br2, I2 have low solubility in water 3 They are already soluble in some organic solvent like CCl4, CS2, ethyl ether and benzene 3 I2 is quite soluble in solution of KI, HI or other iodides: I2+I- I3 )oXIC 6) Dissociation energy Cl2→Br2→I2↓ 2. Chemical properties 1) Oxidizing properties F2→l2↓ dE(F2/F)>E(C1)/CI)>E(Br2/Br)>E(2D) luorine is the most reactive of all the elements in the periodic table. It reacts with all the other elements except the lighter noble gases(He, Ne, ar). Reactions with many elements are vigorous, and often explosive. The reactivity of the other halogens decreases in the order CI>Br>l 2)Reactions of the halogens with water 3 Fluorine is such a strong oxidizing agent that it oxidizes water to oxygen. The large negative free energy change indicates a strongly exothermic and spontaneous reaction: 2F2+2H20 第23页 2006-02-22第 23 页 2006-02-22 23 Color Wavelength Olivine Violet 400-450nm Yellow Blue 450-480nm Orange Greenish blue 480-490nm Red Blue-green 490-500nm Mauve Green 500-560nm Violet Olivine 560-580nm Blue Yellow 580-600nm Greenish blue Orange 600-650nm Blue-green Red 650-750nm E=hν=hc/λ E↑ λ↓ 4) Solubility ○ 1Cl2, Br2, I2 have low solubility in water ○ 2They are already soluble in some organic solvent like CCl4, CS2, ethyl ether and benzene ○ 3 I2 is quite soluble in solution of KI, HI or other iodides: I2 +I- I3 - 5) Toxic 6) Dissociation energy Cl2→Br2→ I2 ↓ 2. Chemical properties 1) Oxidizing properties F2→ I2 ↓ ○ 1Eθ (F2/F- ) >Eθ (Cl2/Cl- ) >Eθ (Br2/Br- ) >Eθ (I2/I- ) ○ 2Fluorine is the most reactive of all the elements in the periodic table. It reacts with all the other elements except the lighter noble gases (He, Ne, Ar). Reactions with many elements are vigorous, and often explosive. The reactivity of the other halogens decreases in the order Cl>Br>I. 2) Reactions of the halogens with water ○ 1 Fluorine is such a strong oxidizing agent that it oxidizes water to oxygen. The large negative free energy change indicates a strongly exothermic and spontaneous reaction: 2F2+2H2O