On treatment of 100 mL of 0.1 M solution of CoCl₃. 6H₂O with excess AgNO₃; 1.2 $$\times$$ 10²² ions are precipitated. The complex is :

The major product obtained in the following reaction is :

The increasing order of the reactivity of the following halides for the S_N1 reaction is :

Given
$$E_{C{l_2}/C{l^ - }}^o$$ = 1.36 V, $$E_{C{r^{3 + }}/Cr}^o$$ = - 0.74 V
$$E_{C{r_2}{O_7}^{2 - }/C{r^{3 + }}}^o$$ = 1.33 V, $$E_{Mn{O_4}^ - /Mn ^{2+}}^o$$ = 1.51 V
Among the following, the strongest reducing agent is :