(1)分液漏斗;Cu+4HNO 3(浓)=Cu(NO 3) 2+2NO 2↑+2H 2O
(2)生成红棕色气体;生成无色气体、蒸馏水中有气泡;3NO 2+H 2O=2H ++2NO 3 -+NO
(3)氧气
(4)黄;红(或“血红”)