In the following brown complex, the oxidation state of iron is +_____________.

$${[Fe{({H_2}O)_6}]^{2 + }} + NO \to \mathop {{{[Fe{{({H_2}O)}_5}(NO)]}^{2 + }}}\limits_{\text{Brown complex}} + {H_2}O$$

Spin only magnetic moment ($$\mu$$_s) of $${K_3}[Fe{(CN)_6}]$$ is ____________ B.M.

(Nearest integer)

$${[Fe{(CN)_6}]^{4 - }}$$

$${[Fe{(CN)_6}]^{3 - }}$$

$${[Ti{(CN)_6}]^{3 - }}$$

$${[Ni{(CN)_4}]^{2 - }}$$

$${[Co{(CN)_6}]^{3 - }}$$

Among the given complexes, number of paramagnetic complexes is ____________.

(a) CoCl₃.4NH₃,    (b) CoCl₃.5NH₃,      (c) CoCl₃.6NH₃    and    (d) CoCl(NO₃)₂.5NH₃.

Number of complex(es) which will exist in cis-trans form is/are _______________.