Hypo is used in photography because of its:

The complex $[Co(NH_3)_5Br]SO_4$ will give a white precipitate with:

In a complexometric titration of a metal ion with a ligand,the reaction is $M$ $(Metal-ion)$ + $L$ $(Ligand)$ $\to$ $C$ $(Complex)$. The end point is estimated spectrophotometrically (through light absorption). If '$M$' and '$C$' do not absorb light and only '$L$' absorbs,then the titration plot between absorbed light $(A)$ versus the volume of ligand '$L$' $(V)$ would look like:

$A$ white precipitate of $AgCl$ dissolves in excess of
$(I)$ $NH_{3(aq)}$
$(II)$ $Na_2S_2O_3$
$(III)$ $NaCN$

Chlorophyll is a

An ammoniacal metal salt solution gives a brilliant red precipitate on the addition of dimethylglyoxime. The metal ion is: