Considering ${\mathrm{H}}_2\mathrm{O}$ as a weak field ligand, the number of unpaired electrons in ${\left[\mathrm{Mn}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$ will be ______.

(At. no. of $\mathrm{Mn}=25$)

In the following compounds, the count of complexes having cobalt in $+3$ oxidation state is:

i. ${\mathrm{Na}}_3\left[\mathrm{Co}{\left({\mathrm{NO}}_2\right)}_6\right]$
ii. $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$
iii. ${\left[\mathrm{Co}(\mathrm{en}{)}_2{\mathrm{Cl}}_2\right]}^{+}$
iv. ${\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$
v. ${\left[{\mathrm{CoCl}}_4\right]}^{2-}$
vi. ${\left[\mathrm{Co}(\mathrm{CN}{)}_6\right]}^{3-}$