题目

Nothing could stop Dad. After he was put on disability for a bad back, he bought a small farm in the country, just enough to grow food for the family. He planted vegetables, fruit trees and even kept bees for honey.     And every week he cleaned Old Man McColgin's chicken house in exchange for manure(肥料). The smell really burned the inside of your nose. When we complained about the terrible smell, Dad said the stronger the manure, the healthier the crops, and he was right. For example, just one of his cantaloupes(甜瓜) filled the entire house with its sweet smell, and the tast（2012?醴陵市模拟）铬化学丰富多彩，由于铬光泽度好，常将铬镀在其他金属表面，同铁、镍组成各种性能的不锈钢，CrO3大量地用于电镀工业中．（1）CrO3具有强氧化性，遇到有机物（如酒精）时，猛烈反应以至着火，若在硫酸溶液中乙醇被氧化成乙酸，CrO3被还原成绿色的硫酸铬[Cr2（SO4）3]．则该反应的离子方程式为4CrO3+3CH3CH2OH+12H+═4Cr3++3CH3COOH+9H2O4CrO3+3CH3CH2OH+12H+═4Cr3++3CH3COOH+9H2O．（2）存在平衡：2CrO42ˉ（黄色）+2H+?Cr2O72ˉ（橙色）+H2O①若平衡体系的pH=2，则溶液显橙色橙色色．②能说明该反应达平衡状态的是bcbc．a．Cr2O72ˉ和CrO42ˉ的浓度相同b．2V正（Cr2O72ˉ）=V逆（CrO42ˉ）c．溶液的颜色不变（3）在图装置中，观察到图1装置铜电极上产生大量的无色气泡，而图2装置中铜电极上无气体产生，铬电极上产生大量有色气体．由图1知金属铬的活动性比铜强强（填强，弱），图2装置中铬电极的电极反应式：NO3-+4H++3eˉ=NO↑+2H2ONO3-+4H++3eˉ=NO↑+2H2O．（4）CrO3和K2Cr2O7均易溶于水，这是工业上造成铬污染的主要原因．净化处理方法之一是将含+6价Cr的废水放入电解槽内，用铁作阳极，加入适量的NaCl进行电解：阳极区生成的Fe2+和Cr2O72ˉ发生反应，生成的Fe3+和Cr3+在阴极区与OHˉ结合生成Fe（OH）3和Cr（OH）3沉淀除去[已知KspFe（OH）3=4.0×10-38，KspCr（OH）3=6.0×10-31]．①电解过程中NaCl的作用是增强溶液的导电性增强溶液的导电性．②已知电解后的溶液中c（Fe3+）为2.0×10-13mol/L，则溶液中c（Cr3+）为：3.0×10ˉ63.0×10ˉ6mol/L．