题目

某溶液可能含有Cl-、SO42-、CO32-、NH4+、Fe3+、Al3+和K+。取该溶液100mL，加入过量NaOH溶液，加热，得到0.02mol气体，同时产生红褐色沉淀；过滤，洗涤，灼烧，得到1.6g固体；向上述滤液中加足量BaCl2溶液，得到4.66g不溶于盐酸的沉淀。由此可知原溶液中 A.至少存在5种离子 B. SO42-、NH4+、一定存在，Cl-可能不存在 C. Cl-一定存在，且c（Cl‑）≥0.4mol/L D.CO32-、Al3+一定不存在，K+可能存在听下面5段对话,每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置.听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题.每段对话仅读一遍.1. How long did the woman wait at the airport?A. Two hours.B. Three hours.C. Five hours2. What can we learn about the man?A. He is modest.B. He is satsfied.C. He is upset.3. Where is George now?A. Europe.B. Canada.C. America4. What's the man's suggestion to the woman?A. Having confidence in her son.B. Teaching her son by herself.C. Asking the teacher for extra help.5. What can we learn from the conversation?A. Neither of them likes the football match.B. Both of them like the football match.C. One likes the football match, but the other doesn't.