Nếu cho 1 mol mỗi chất:

C

- Hướng dẫn giải

Đáp án C

$CaOC{l}_2$ + 2HCl → $CaC{l}_2$ + $C{l}_2$ + $H_{2}O$

1                                             1              mol

2$KMn{O}_{4 }$+ 16HCl → 2KCl + 2$MnC{l}_2$ + 5$C{l}_2$ + 8$H_{2}O$

1                                                              2,5             mol

$K_{2}C{r}_2{O}_7$ + 14HCl → 2KCl + 2$CrC{l}_3$ + 3$C{l}_2$ + 7$H_{2}O$

1                                                                3              mol

$Mn{O}_2$ + 4HCl → $MnC{l}_2$ + $C{l}_2$ + 2$H_{2}O$

1                                             1               mol

Vậy nếu cho cùng 1 mol mỗi chất $CaOC{l}_2, KMn{O}_4, K_{2}C{r}_2{O}_7,$ MnO₂ thì $K_{2}C{r}_2{O}_7$ cho lượng khí $C{l}_2$ nhiều nhất.