题目

根据短文理解完成下列各题。 Mrs. Green had a young dog which was very clever. It often helped her buy a newspaper. One winter evening, the dog went out to play. It was snowing heavily. Soon the ground(地面) became white. “The dog never loses his way. Where is he now?” Mrs. Green thought. She shouted(喊) his name. But still the dog didn't come back. So she telephoned the police and told them a lot about her dog. “My dog is very clever. He always goes out and comes back soon. Sometimes he plays with his friend, Mickey. He can buy a newspaper. He almost talks.” The policem7．某科研小组设计如图所示装置，利用甲烷碱性燃料电池电解工业酸性含铬废水（主要含Cr2O72-）．电解池中用Fe作电极电解含Cr2O72-的酸性废水，随着电解进行，在阴极附近溶液pH升高，产生Cr（OH）3．回答下列问题：（1）燃料电池负极的反应式为：CH4+10OH--8e-=CO32-+7H2O．（2）用该方法处理废水时，若有0.01mol Cr2O72-．完全反应时，最后得到沉淀的质量至少是2.06g．