皮皮学，免费搜题
登录
搜题
【单选题】
CuI是一种不溶于水的白色固体，它可以由反应：2Cu 2+ +4I - =2CuI↓+I 2 而得到。现以石墨为阴极，以Cu为阳极电解KI溶液，通电前向电解液中加入少量酚酞和淀粉溶液。电解开始不久，阴极区溶液呈红色，而阳极区溶液呈蓝色，同时有白色沉淀生成。下列说法中正确的是A.
对阳极区溶液呈蓝色的正确解释是：2I - -2e - =I 2 ，碘遇淀粉变蓝
B.
对阳极区溶液呈蓝色的正确解释是：Cu-2e - =Cu 2+ ，Cu 2+ 显蓝色
C.
阴极区溶液呈红色的原因是：2H + +2e - =H 2 ↑，使阴极附近OH - 浓度增大，溶液显碱性，从而使酚酞变红
D.
阴极上的电极反应式为：Cu 2+ +2e-=Cu
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【单选题】有 10 名成年人和 10 名幼儿的身高资料如下所示: 成年人: 173 169 172 180 177 170 172 174 168 166 幼儿: 69 68 70 68 71 73 72 73 74 75 幼儿组身高的变异系数为()
A.
0.025
B.
0.035
C.
0.027
D.
0.034
【单选题】--What’s the _________of her birth? --It’s June eighth.
A.
date
B.
day
C.
birthday
D.
month
【单选题】Beyonce, a leading ______ in the music industry, gave birth to her daughter on Saturday. [ ]
A.
statue
B.
figure
C.
brand
D.
attraction
【单选题】Today is her birthday. She__________all of her friends to the birthday party.
A.
invited
B.
asked for
C.
hoped
D.
contract
【简答题】When Joan gave birth to the first boy in her family in three generations, she and her husband were overjoyed. So were her parents. Joan expected her elder sister, Sally, to be just as delighted as the...
【单选题】患者女性,30岁。3天前右手食指末节指腹不慎刺伤,现食指皮肤苍白,肿胀明显,自感有搏动性跳痛,疼痛剧烈,患肢下垂时尤重,应采取的方法是( )
A.
注射哌替啶
B.
局部纵行切口引流
C.
局部热敷
D.
局部冰敷
相关题目：
参考解析：
知识点：
题目纠错 0
发布
