问题 实验题

某校化学实验兴趣小组在“探究溴水与氯化亚铁溶液反应”的实验中发现:在足量的稀氯化亚铁溶液中,加入1-2滴溴水,振荡后溶液呈黄色。查阅资料显示:溴水是溴(Br2)的水溶液,呈黄色;溴水中含有溴单质。

⑴提出问题:溴水能否与氯化亚铁溶液反应

⑵猜想:

①甲同学认为:不能,故上述实验现象不是发生化学反应所致,则溶液呈黄色是含                   (填化学式,下同)所致

②:能,故上述实验现象是发生化学反应所致,则溶液呈黄色是含               所致。

⑶设计实验并验证丙同学为验证乙同学的观点,选用下列某些试剂设计出两种方案进行实验,并通过观察实验现象,证明了乙同学的观点确实是正确的。除氯化亚铁溶液和溴水外,还有供选用的试剂:a、酚酞试液;b、CCl4;c、无水酒精;d、KSCN溶液。请你在下表中写出丙同学选用的试剂及实验中观察到的现象(试剂填序号)

选用试剂实验现象
方案1
方案2

⑷结论:溴水能与氯化亚铁溶液反应。故在足量的稀氯化亚铁溶液中,加入1-2滴溴水,溶液呈黄色所发生的离子反应方程式为                                     ⑸实验后的思考该兴趣小组在查阅资料同时得知:在溴化亚铁溶液中通入Cl2,Cl2先将Fe2+完全氧化成Fe3+后,再与 Br-反应。根据上述信息,试回答:在100mLFeBr2溶液中通入2.24LCl2(标准状况),溶液中有1/2的Br被氧化成Br2,则原FeBr2溶液中FeBr2的物质的量浓度为              

答案

(2)①Br2②Fe3+

(3)b;CCl4层呈无色

d;溶液变成红色

(4)2Fe2++Br2==2Fe3++2Br-

(5)1mol/l

单项选择题
阅读理解

Most students in China have their own school rules. So do the schools in other countries.

Japan: Most schools demand(要求) that students wear uniforms, such as sports suits or skirts. They also demand that girls’ white socks be folded in a certain way and boys’ heads be shaved(剃)

Other Japanese schools tell students that they may not date, go to movies, leave home after sunset or play video games without permission from school.

USA: For safety at home USA schools, students must have a pair of indoor shoes to change into at school every day. This makes sure students won’t fall over on the slippery floors and keeps the schools clean. Gum chewing is not allowed in many USA school buildings, as it is difficult to clean up. And if students chew gum in class, they may not focus on study.

UK: Strange hairstyles are not allowed in some British schools. But they might allow students to wear certain hairstyles during the World Cup years. Two students had a special design shaved into their hair during 2002 World Cup. But they were not accepted by their school after that because the school said the rules changed since then.

小题1:Many Japanese students have to follow the following rules EXCEPT       .

A.wear uniform

B.boys’ heads should be shaved

C.wear indoor shoes at school

D.can’t leave home after sunset小题2:Gum chewing is not allowed in many USA schools may because           .

A.it is difficult to clean up

B.make students study carefully

C.it costs students too much money

D.it wastes teachers’ time小题3:British students could have a special hairstyle         .

A.during Olympic Games

B.in the year 2007

C.only during the World Cup

D.after the school rules changed小题4:The meaning of the focus on is           .

A.从事于

B.继续

C.专心于

D.放弃小题5:The passage wants to tell us            .

A.Different countries have the same rules for the students

B.We must follow all the rules above

C.Students in different countries have to follow different rules

D.Most schools in China have different school rules