问题 填空题

已知A和B两支试管所盛的溶液中共含有K、Ag、Mg2、Cl、OH、NO3六种离子,向试管A的溶液中滴入酚酞试液呈粉红色。请回答下列问题:

(1)试管A的溶液中所含的离子是_______________________。

(2)若向试管B的溶液中加入合适的药品,过滤后可以得到相应的金属和仅含一种溶质的溶液,则加入的药品是___ _______(填化学式)。

(3)若试管A和试管B中的溶液是由等物质的量的四种物质配成的溶液,将两试管中溶液混合后过滤,所得滤液中各种离子的物质的量之比为__                        ______。

答案

(1)K+、OH-、Cl-  (2)Mg  (3)n(K)∶n(Mg2)∶n(NO3)=4∶1∶6

向试管A的溶液中滴入酚酞试液呈粉红色,说明溶液显碱性,因此A中含有OH,但不能含有Ag、Mg2。又因为银离子和氯离子不能大量共存,所以氯离子在A中。由于溶液是显中性的,所以A中还含有钾离子。所以B中含有的离子是Ag、Mg2、NO3

(2)银是重金属,加入镁能置换出银,最终得到氯化镁,所以该试剂是镁。

(3)若试管A和试管B中的溶液是由等物质的量的四种物质配成的溶液,则混合后恰好生成氯化银沉淀,同时还生成氢氧化镁沉淀,但镁离子过量,所以所得滤液中的离子分别是K、Mg2、NO3,其n(K)∶n(Mg2)∶n(NO3)=4∶1∶6

阅读理解

Have you ever suddenly felt that someone you know was in trouble—and he was? Have you ever dreamed something that came true later? Maybe you have ESP.

ESP stands for(代表) Extra Sensory Perception. It may be called a sixth sense. It seems to let people know about events before they happen, or events that are happening some distance away.

Here is an example: A woman was doing washing. Suddenly she screamed, “My father is dead!” I saw him sitting in the chair!” Just then. a telegram came. The woman’s father had died of a heart attack. He died sitting in a chair.

There are thousands of stories like this on record. Scientists are studying them to find out what is behind these strange mental messages. Here’s another example—one of hundreds of dreams that have come true.

A man dreamed he was walking along a road when a horse and carriage came by. The driver said, “There’s room for one more.” The man felt the driver was dead, so he ran away. The next day the man was getting on a crowded bus. The bus driver said, “There’s room for one more.” Then the man saw the driver’s face was the same face he had seen in the dream. He wouldn’t get on the bus. As the bus drove off, it crashed and burst into flames. Everyone was killed!

Some people say stories like these are lies or coincidences. Others, including some scientists say that ESP is true. From studies of  ESP, we may some day learn more about the human mind.

小题1:People with ESP may know about ____________

A.someone’s trouble

B.events before they happen

C.their dreams

D.events after they happen小题2: From the passage it can be inferred that ____________.

A.all people have ESP

B.some women or men have ESP

C.children have ESP

D.no have ESP

综合