(不纯)HBr:NaBr(s)+H2SO4(浓)→HBr↑ 2HBr+H2SO4()→↑Br2↑+SO2↑+2H2O (不纯)HⅡ：8HI+H2SO4() →H2S+L2+4H20 常用：3Br(I+2P+6H2O=2H3P03+6HB (Br2滴到P+H2O中) 即：PBr3和PL3水解，较剧烈 6H20+2P+3I2=2H3PO3+6HI↑（水滴到 P+L2中) (不纯)HBr: NaBr(s)+H2SO4(浓) →HBr↑ 2HBr+H2SO4(l) →↑Br2↑+SO2↑+2H2O （不纯）HI: 8HI+H2SO4(l) →H2S+I2+4H2O 常用： 3 Br(l)+2P+6H2O=2H3PO3+6HBr (Br2滴到P+H2O中) 即：PBr3和PI3水解，较剧烈 6H2O+2P+3I2=2H3PO3+6HI↑（水滴到 P+I2中）