Đáp án:

Giải thích các bước giải:

 27 ) Ca(oh)2 + 2hbr -> cabr2 + 2h2o
28 ) Ca(oh)2 + 2hcl -> cacl2 + 2h2o
29 ) Ca(oh)2 + h2so4 -> caso4 + 2h2o
30 ) Ca(oh)2 + na2co3 -> caco3 + 2naoh
31 ) na2s + h2so4 -> na2so4 + h2s
32 ) na2s + 2hcl -> 2nacl + h2s
33 ) 2k3po4 + 3mg (oh)2 -> 6koh + mg3(po4)2

Em tham khảo nha:

\(\begin{array}{l}
27)\,Ca{(OH)_2} + 2HBr \to CaB{r_2} + 2{H_2}O\\
28)\,Ca{(OH)_2} + 2HCl \to CaC{l_2} + 2{H_2}O\\
29)\,Ca{(OH)_2} + {H_2}S{O_4} \to CaS{O_4} + 2{H_2}O\\
30)\,Ca{(OH)_2} + N{a_2}C{O_3} \to CaC{O_3} + 2NaOH\\
31)\,N{a_2}S + {H_2}S{O_4} \to N{a_2}S{O_4} + {H_2}S\\
32)N{a_2}S + 2HCl \to 2NaCl + {H_2}S\\
33)\,2{K_3}P{O_4} + 3Mg{(OH)_2} \to 6KOH + M{g_3}{(P{O_4})_2}
\end{array}\)