题目

The trouble of having to charge your smart phone for hours a day could become a thing of the past. British scientists have created a material that replaces the screen glass for phones, i-pad and smartwatches, but uses no power—meaning they could be charged weekly. The discovery is important because more than 90 percent of a device’s battery power illuminates（照明）the screen. Technology firms have focused on improving battery life. But the British experts say dealing with the main power-using may give better results. Oxford University engineer Dr Peiman Hosseini, who invente（2012?宁德模拟）反应：Cr2O72-+3SO32-+aH+=2Cr3++3Y+4H2O下列说法不正确的是（　　）A．Y是SO42-B．a=8C．Cr2O72-被氧化成Cr3+D．生成1molCr3+时转移的电子数是3×6.02×1023