Bài 3. Cho phản ứng: \({K_2}C{r_2}{O_7} + HCl\buildrel {} \over \longrightarrow KCl + CrC{l_3} + {H_2}O + C{l_2}\)Trong phản ứng này có bao nhiêu phân tử \(HCl\) bị oxi hóa?\(\eqalign{ & A.3\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B.6 \cr & C.8\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,D.14 \cr} \)Giải:Chọn B\({K_2}C{r_2}{O_7} + 14HCl\buildrel {}...