C2H4O2+K2Cr2O7+H2SO4----K2SO4+Cr2(SO4)3+CO2+H2OK2Cr2O7+KI+H2SO4----K2SO4+Cr2(SO4)3+I2+H2OAs2S3+HNO3+H2O----H3AsO4+H2SO4+NOFe3O4+KMnO4+H2SO4----Fe2(SO4)3+MnSO4+K2SO4+H2OCuSO4+FeS2+H2O----Cu2S+FeSO4+H2SO4
参考资料:根据化合价升降就行了