Cho các phản ứng: (a) (b) (c) (d) Phản ứng có phương trình ion thu gọn: là:

* Hướng dẫn giải

(a) \(\left\{ \begin{gathered} Pha{\text{n tu:Fe(OH}}{{\text{)}}_2} + 2HCl \to FeC{l_2} + 2{H_2}O \hfill \\ Ion:Fe{(OH)_2} + 2{H^ + } \to F{e^{2 + }} + 2{H_2}O \hfill \\ \end{gathered} \right.\)

(b) \(\left\{ \begin{gathered} Pha{\text{n tu:Ba(OH}}{{\text{)}}_2} + {H_2}S{O_4} \to BaS{O_4} \downarrow + 2{H_2}O \hfill \\ Ion:\left| \begin{gathered} B{a^{2 + }} + SO_4^{2 - } \to BaS{O_4} \downarrow \hfill \\ {H^ + } + O{H^ - } \to {H_2}O \hfill \\ \end{gathered} \right. \hfill \\ \end{gathered} \right.\)

(c) \(\left\{ \begin{gathered} Pha{\text{n tu:KHC}}{{\text{O}}_3} + KOH \to {K_2}C{O_3} + {H_2}O \hfill \\ Ion:HCO_3^ - + O{H^ - } \to CO_3^{2 - } + {H_2}O \hfill \\ \end{gathered} \right.\)

(d) \(\left\{ \begin{gathered} Pha{\text{n tu:Ba(OH}}{{\text{)}}_2} + 2HCl \to BaC{l_2} + 2{H_2}O \hfill \\ Ion:{H^ + } + O{H^ - } \to {H_2}O \hfill \\ \end{gathered} \right.\)

Đáp án B.