在硫酸-磷酸介质中,用K<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub>滴定Fe<sup>2+</sup>时,其化学计量点电位为0.86V,则选择的指示剂为()
A、二苯胺(Eθ=0.76V)
B、邻二氮菲-Fe2+(Eθ=1.06V)
C、亚甲基蓝(Eθ=0.53V)
D、二苯胺磺酸钠(Eθ=0.89V)
A、二苯胺(Eθ=0.76V)
B、邻二氮菲-Fe2+(Eθ=1.06V)
C、亚甲基蓝(Eθ=0.53V)
D、二苯胺磺酸钠(Eθ=0.89V)
A、将AgN0<sub>3sub>滴定液装在碱式滴定管中 B、将K<sub>2sub>Cr<sub>2sub>O<sub>7sub>滴定液装在碱式滴定管中 C、以K<sub>2sub>Cr<sub>2sub>O<sub>7sub>标定Na<sub>2sub>S<sub>2sub>0<sub>3sub>溶液时用碘量瓶 D、上述滴定(C)中,淀粉指示剂宜在近终点时加入 E、用EDTA滴定液直接滴定Al3+时,滴定速度应快
A、K<sub>2sub>CrO<sub>4sub> B、K<sub>2sub>Cr<sub>2sub>O<sub>7sub> C、NH<sub>4sub>Fe(SO<sub>4sub>)<sub>2sub> D、荧光黄
A、As<sub>2sub>O<sub>3sub> B、ZnO C、K<sub>2sub>Cr<sub>2sub>O<sub>7sub> D、Na<sub>2sub>CO<sub>3sub>
A、ZrOCl<sub>2sub>(氧氯化锆 B、K<sub>2sub>S<sub>2sub>O<sub>8sub> (过硫酸钾) C、NH<sub>2sub>-NH<sub>2sub> (联氨) D、RCOONa (脂肪酸钠皂)
A、k<sub>1sub>[A]-k<sub>2sub>[D][B] B、k<sub>1sub>[A]-k<sub>-1sub>[B]-k<sub>2sub>[D][B] C、k<sub>1sub>[A]-k<sub>-1sub>[B]+k<sub>2sub>[D][B] D、-k<sub>1sub>[A]+k<sub>-1sub>[B]+k<sub>2sub>[D][B]
A、E<sub>1sub>=E<sub>2sub>;K<sub>1sub>=K<sub>2sub> B、E<sub>1sub>≠E<sub>2sub>;K<sub>1sub>=K<sub>2sub> C、E<sub>1sub>=E<sub>2sub>;K<sub>1sub>≠K<sub>2sub> D、E<sub>1sub>≠E<sub>2sub>;K<sub>1sub>≠K<sub>2sub>
A、K257;<sub>1sub>=K257;<sub>2sub> B、K257;<sub>1sub>=2K257;<sub>2sub> C、K257;<sub>1sub>=1/2K257;<sub>2sub> D、K257;<sub>1sub>=(K257;<sub>2sub>)2
A、K<sub>2sub>CrO<sub>7sub> B、K<sub>2sub>Cr<sub>2sub>O6 C、K<sub>2sub>CrO<sub>4sub> D、K<sub>2sub>Cr<sub>2sub>O<sub>7sub>