Among the following complexes, the total number of diamagnetic species is ___________.

$\left[\mathrm{Mn}\left(\mathrm{NH}_3\right)_6\right]^{3+},\left[\mathrm{MnCl}_6\right]^{3-},\left[\mathrm{FeF}_6\right]^{3-},\left[\mathrm{CoF}_6\right]^{3-},\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_6\right]^{3+}$, and $\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}$

[Given, atomic number: $\mathrm{Mn}=25, \mathrm{Fe}=26, \mathrm{Co}=27$;

$$ \text { en } \left.=\mathrm{H}_2 \mathrm{NCH}_2 \mathrm{CH}_2 \mathrm{NH}_2\right] $$

The total number of possible isomers for [Pt(NH₃)₄Cl₂]Br₂ is ______.

Total number of $$cis\,N - Mn - Cl$$ bond angles (that is $$Mn - N$$ and $$Mn - Cl$$ bonds in cis positions) present in a molecule of $$cis[Mn{(en)_2}C{l_2}]$$ complex is ..................

(en = NH₂CH₂CH₂NH₂)

The ammonia prepared by treating ammonium sulphate with calcium hydroxide is completely used by $$NiCl{}_2.6{H_2}O$$ to form a stable coordination compound. Assume that both the reactions are $$100\% $$ complete. If $$1584$$ $$g$$ of ammonium sulphate and $$952\,g$$ of $$NiC{l_2}.6{H_2}O$$ are used in the preparation, the combined weight (in grams) of gypsum and the nickel-ammonia coordination compound thus produced is _____________.

(Atomic weights in $$g$$ $$mo{l^{ - 1}}:$$ $$H = 1,N = 14,O = 16,$$ $$S = 32,Cl = 35.5,$$ $$Ca = 40,$$ $$Ni = 59$$