题目

When my son, Mark, was in the third grade, he saved all his pocket money for over three months to buy holiday presents. The third Saturday in December Mark said he had made his list and had twenty dollars in his pocket. I drove him to a nearby supermarket. Mark picked up a hand basket and went in while I waited and watched in the car. It took Mark over 45 minutes to choose his presents. Finally he came to the checkout counter (交款处) and reached into his pocket for his money. It was not there! There was a hole in his pocket, but no money. Mark stood there holding his basket, tears1．如图是制取二氧化碳并进行有关物质的性质实验的装置，请根据要求回答有关问题．（1）写出下列装置中的化学方程式：装置A：CaCO3+2HCl=CaCl2+H2O+CO2↑；装置G：Fe2O3+3CO$\frac{\underline{\;高温\;}}{\;}$2Fe+3CO2．（2）实验过程中装置B中的现象是液体由紫色变红色；装置F的作用为检验二氧化碳是否被除净．（3）将A中的稀盐酸不断滴入大理石后，应先点燃D （选填D或G）处的酒精灯．（4）充分反应前后G、H装置的质量分别表示于下表中：GH反应前（g）57.840.2反应后（g）55.444.6则样品中氧化铁的质量为8g．（5）该装置有一处明显的不足，请给出改进的具体措施添加尾气处理装．