题干

全钒液流电池充电时间短,续航能力强,其充放电原理为VO2++V3++H2O VO2++V2++2H+。以此电池为电源,用石墨电极电解Na2SO3溶液,可得到NaOH和H2SO4示意图如下。下列说法错误的是(    )

A:全钒液流电池放电时,正极的电极反应式为VO2++2H++e-=VO2++H2O

B:图中a电极为阴极,N物质是H2

C:全钒液流电池充电时,V3+被氧化为VO2+

D:电解时,b电极的反应式为SO32-+H2O-2e-=SO42-+2H+

上一题 下一题 0.0难度 选择题 更新时间:2014-12-09 06:06:58

答案(点此获取答案解析)

C

同类题5

完形填空

    Twenty years ago, I drove a taxi for a living. One early morning, I1 a call for a taxi. When I arrived at the building, it was 2:30 a.m. and I found the building was dark except for the only light in a first floor window.

    Many drivers would just shout once or twice and then drove away, but I thought this 2 might need my help. So I walked to the door and knocked, “Just a minute,” answered a3, elderly voice. After a long time, the door opened. A small old man showed up before me,4a small bag. He kept thanking me for my5. “It's nothing,” I told him.

    “Oh, you're such a good man.” He said. When we got into the taxi, he gave me a (an)6, and then asked, “Could you drive through the city center?”

    “But it wasn't the7way.” I answered quickly. “Oh, I'm in no hurry.” He said. “I'm on my way to a hospital. I don't have any family left. The 8 says I don't have much time left.

    I 9 started the taxi and shut off the meter(计程器). For the next two hours, we drove through the city center. He showed me the building where he once worked. We drove10 the church where he got married. He would never forget that happy moment. Sometimes he'd ask me to slow down in front of a building and would sit11the darkness for a long time, saying nothing. When the sun began to rise, we drove in silence to the address he had given me. When we arrived,12 without thinking, I gave him a big hug. “You gave an old man a little moment of13. Thank you!” He said with tears in his eyes.

    I was completely lost in thought for the rest of the day. What would happen if I had refused to do14 I did? We always think that there are no15 moments in our lives, but great moments are just in what others may think small and unimportant ones!