问题 选择题

下列说法不正确的是(  )

①将SO2通入溶有足量氨的BaCl2溶液中,无白色沉淀生成

②将盐酸、KSCN 溶液和Fe(NO3)2溶液三种溶液混合,混合溶液显红色

③向某溶液中滴入盐酸酸化的BaCl2溶液产生白色沉淀,证明溶液中一定含有SO42-

④将两小块质量相等的金属钠,一块直接投入水中,另一块用铝箔包住,在铝箔上刺些小孔,然后按入水中,两者放出的氢气质量相等

⑤使用明矾可以对水进行消毒、杀菌

A.只有②

B.①②③⑤

C.①③④⑤

D.①②③④

答案

答案:C

题目分析:①将SO2通入溶有足量氨的BaCl2溶液中,有白色沉淀生成,可以理解成氨先跟二氧化硫起反应生成亚梳酸氨,然后亚硫酸胺跟氯化钡发生复分解生成亚硫酸钡沉淀,因此该说法错误;②将盐酸、KSCN 溶液和Fe(NO3)2溶液三种溶液混合,混合溶液显红色,正确,因为在酸性条件下,硝酸根离子有强的氧化性,可以将二价铁离子氧化成三价,三价铁离子可以遇到硫氰化钾显红色;③向某溶液中滴入盐酸酸化的BaCl2溶液产生白色沉淀,证明溶液中一定含有SO42-,不正确,因为溶液中含有银离子的话,也会出现同样的现象;④将两小块质量相等的金属钠,一块直接投入水中,另一块用铝箔包住,在铝箔上刺些小孔,然后按入水中,两者放出的氢气质量相等,不正确,因为钠跟水反应生成的氢氧化钠也能跟铝反应产生氢气;⑤使用明矾可以对水进行消毒、杀菌,错误,明矾只能对水进行净化,但是不能起到消毒、杀菌的作用。因此选C。

阅读理解

阅读理解。

    One afternoon, Henry, an old man from America, telephoned from the airport to tell me that he had arrived.

He was going to stay with me. I was still at the office at the time, but I had prepared for his coming. After

explaining where my new house was, I told him where I had left the key. As I was likely to be home rather late,

I asked him to go into the kitchen and help himself to food and drink.

    Two hours later my friend telephoned me from the flat. At the moment, he said, he was listening to some of

my records after having just had a truly wonderful meal. He had cooked two eggs and had helped himself to

some cold chicken from the refrigerator.

     Now, he said, he was drinking a glass of orange juice and he hoped I would join him. When I asked him if

he had reached the flat without difficulty he answered that he had not been able to find the key, but luckily the

living-room window just by the apple tree had been left open and he had climbed in. I listened to all this in

surprise. There is no apple tree in front of my living-room, but there is one in front of my neighbour's!

1. I knew that Henry would _____. [ ]

A. call at my office

B. arrive

C. telephone me from the airport

D. meet my neighbour

2. I asked him to go into the kitchen and help himself to food and drink because _____. [ ]

A. he was very hungry

B. he liked good food

C. I would very probably be home late

D. I disliked being bothered

3. Henry said he was listening to some of the records _____. [ ]

A. before he had a meal

B. because he had nothing to do

C. because he wasn' t hungry

D. after he had had a wonderful meal

4. When Henry telephoned me from the flat he was _____. [ ]

A. listening to some records

B. drinking a glass of orange juice

C. doing nothing

D. both A and B

5. Henry entered the house _____. [ ]

A. without difficulty

B. as he had been told to

C. through the open window

D. by opening the door with the key

单项选择题