Hello! I'm Linda. I have a good e-friend. Her name is Zhang Yun. Her English name is Betty. She is a Chinese girl, but she lives in the UK with her parents. Her father is a doctor and her mother is a teacher. She is ten years old. She call me big sister. She is good at English. She likes Chinese and I also like Chinese. She likes singing and playing basketball. This is my good e-friend. Do you want to know more?

以下说法正确的是（   ）

实验室模拟合成氨和氨催化氧化的流程如下，气体混合的装置如图甲所示，合成氨的装置如图乙所示，氨吸收和氨氧化的装置如图丙所示．

（1）已知实验室可用饱和亚硝酸钠（NaNO₂）溶液与饱和氯化铵溶液经加热后反应制取氮气．则制取氮气的装置为____ （从图A、B、C中选择，下同），制取氢气的装置为____ ．

（2）甲装置的作用除了使气体充分混合外，还有①____ 、②____ ．

（3）乙装置发生反应的化学方程式为____ ．其中催化剂为Fe粉，它能否用Fe₂O₃代替？____ ．说明理由____ ．

（4）丙装置吸收一段时间氨气后，再通入空气，同时将经加热的铂丝插入到锥形瓶内，可观察到：有红棕色气体和白烟生成，请用化学方程式说明催化氧化后，产生以上现象的原因：____ ；____ ，____ 　．