交警常用装有重铬酸钾(K2Cr2O7)的仪器检测司机是否酒后开车,因

交警常用装有重铬酸钾(K2Cr2O7)的仪器检测司机是否酒后开车,因为酒中的乙醇分子可以使橙红色的重铬酸钾变为绿色的硫酸铬[Cr2(SO4)3],重铬酸钾和硫酸铬中铬元素的化合价依次是

A+3+4       B+5+3      C+6+3       D+3+6

答案

C

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