问题 选择题

如图是甲醇/过氧化氢燃料电池内部结构示意图。 工作时,甲醇和过氧化氢分别进入燃料电池的燃料腔和氧化剂腔,在各自催化剂的作用下发生反应,并向外界输出电能。下列说法不正确的是

A.该电池的正极反应式:H2O2+2H++2e=2H2O

B.燃料腔中的多孔石墨电极为该燃料电池的负极,负极产生的H+通过质子交换膜流向正极

C.电池工作时,1 mol甲醇被氧化有6 mol电子转移

D.电路中的电子经正极、负极、质子交换膜后再回到正极,形成闭合回路

答案

答案:D

题目分析:根据题给装置图分析,通入甲醇的电极为原电池的负极,发生氧化反应,电极反应式为CH3OH-6e-+H2O=CO2+6H+,加入H2O2的电极为原电池的正极,发生还原反应,电极反应式为H2O2+2H++2e-=2H2O。A、加入H2O2的电极为原电池的正极,发生还原反应,电极反应式为H2O2+2H++2e-=2H2O,正确;B、原电池中阳离子移向正极,故负极产生的H通过质子交换膜流向正极,正确;C、负极电极方程式为CH3OH-6e-+H2O=CO2+6H+,电池工作时,1mol甲醇被氧化有6mol电子转移,正确;D、电路中的电子经负极经外电路流向正极,电子不能经过电解质溶液,错误。

单项选择题
填空题

用下列方框中单词填空。

A. mean  B. make up  C. personal  D. regular  E. bet

F. correct  G. judgement  H. stand for  I. resource  J. especially   

      Twenty years ago,kids in school had never heard of the Internet.  Now, 1      1      you can't find a

single person in your school who hasn't at least heard of it.  In fact,many of us use it on a      2      basis

and even have access to it from our homes! The "net" in "intemet" should     3     network. A network is

two or more computers connected together so that information can.be shared,or sent from tree computer

to another.  The Intemet is a vast    4      for all types of infor- mation. You may enjoy using it to do

research for a school project,downloading your favorite songs or communicating with friends and family.

Information is accessed through web pages that companies,organizations and individuals create and post.

  It's kind of like a giant bulletin board that the whole world uses ! But since anyone can put anything on

the Internet,you also have to be careful and use your best     5     and a little common sense.

      Just because you read something on a piece of paper someone sticks on a bulletin board,it doesn't     6      it's good information,or even     7   . So you have to be sure that whoever posted the

information knows what they're talking about,    8    if you're doing research! But what if you're just

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communicating with online,you could be on dangerous ground ! You should never give out any     9 

   information to someone you don't know,not even your name! And just like you can't believe the

information on every website out there,you can't rely on what strangers you "meet" on the Intemet tell you

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to you!