A.利用铝热反应焊接钢轨: \(\rm{2Al + Fe_{2}O_{3}\begin{matrix}高温 \\ =\end{matrix} }\) \(\rm{2Fe + Al_{2}O_{3}}\) |
B.用氯水除去\(\rm{FeCl_{3}}\)溶液中的\(\rm{Fe}\)\(\rm{{\,\!}^{2+}}\): \(\rm{Cl}\)\(\rm{{\,\!}_{2}}\) \(\rm{+ Fe}\)\(\rm{{\,\!}^{2+}}\) \(\rm{═ 2Cl}\)\(\rm{{\,\!}^{-}}\) \(\rm{+ Fe}\)\(\rm{{\,\!}^{3+}}\) |
C.用已知浓度的\(\rm{NaOH}\)溶液测定未知浓度的醋酸溶液的浓度:\(\rm{H^{+}}\) \(\rm{+ OH}\)\(\rm{{\,\!}^{-}}\) \(\rm{═ H}\)\(\rm{{\,\!}_{2}}\)\(\rm{O}\) |
D.盛放\(\rm{NaOH}\)溶液的试剂瓶不能用玻璃塞:\(\rm{SiO_{2}}\) \(\rm{+ 2Na}\)\(\rm{{\,\!}^{+}}\) \(\rm{+ 2OH}\)\(\rm{{\,\!}^{-}}\) \(\rm{═ Na}\)\(\rm{{\,\!}_{2}}\)\(\rm{SiO}\)\(\rm{{\,\!}_{3}}\) \(\rm{+ H}\)\(\rm{{\,\!}_{2}}\)\(\rm{O}\) |