问题 填空题

H2O2是在医疗、化工方面应用广泛的化学试剂。

(1)Na2O2、CaO2以及BaO2都可与酸作用生成过氧化氢,实验室通过上述某种过氧化物与适量稀硫酸作用,过滤后即可制得较纯净的H2O2溶液,则应选择的过氧化物是________;

(2)实验室可用H2O2与次氯酸钠反应制氧气, 其中还原剂是__________,写出反应的化学方程式______________,生成0.5mol氧气,转移电子_______mol;

(3)用酸性高锰酸钾溶液滴定法可测定双氧水中H2O2的含量,有两位同学分别用以下化学方程式表示其中的反应原理:

①5H2O2+2KMnO4+3H2SO4→2MnSO4+K2SO4+5O2↑+8H2O

②3H2O2+2KMnO4+3H2SO4→2MnSO4+K2SO4+4O2↑+6H2O

你认为其中错误的是_______(认为没有可以不填),简述理由__________________。

答案

(1)BaO2(1分)

(2)H2O2(1分)  H2O2+ NaClO→H2O +NaCl+ O2(2分)  1(2分)

(3)②(1分),该反应实质是H2O2被氧化,-2价氧元素的化合价没有发生变化

听力题

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第Ⅱ卷(共35 分)

第四部分:写作(共两节,满分35 分)

第一节 阅读下面对话,掌握其大意,并根据所给首字母的提示,在标有题号的右边横线上写出一个英语单词的完整、正确的形式,使对话通顺。

A:Hello.

B:Hello.Ann,this is Jenny.I’m calling to see if you could give me

some (76)a_________.I’m going to Shanghai next month.and                    76._____    

It’s the first time I went abroad.I know you went to Shanghai last

year,so maybe you could help me.

A:I’d be happy to.You know,it’s very important to make

(77)p_________before you go abroad.Read about the country and cities          77.____   

you are going to and find out about hotels,(78)t _________                     78._____   

and places to visit.Buy a good map so that you can

find your way around when you get there.

B:Thanks.What about money and things like (79)p_________and visas?       79.____  

A:Good question.It’s not always safe to bring cash,so I

suggest that you use travelers’(80)c_________.You may need a                          80.____   

small (81)a_________of cash when you travel but don’t bring too much           81.____

Most important,never (82)e_________money with someone you                 82.____   

meet on the street.It’s illegal and (83)d_________.As for visas,you           83.____   

need one for some countries.Find out if you need one then (84)a_________for it. 84.____   

B:Thank you,that’s very (85)h_________.                                      85.____   

A:You’re welcome.Enjoy your trip and send me a post card.

操作题