The colour of $(NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot 24H_2O$ is

Which of the following complexes contains an anionic ligand?

The molecular formula of potash alum is

Excess of silver nitrate solution is added to $100 \ mL$ of $0.01 \ M$ pentaaqua chloro chromium $(III)$ chloride solution. The mass of silver chloride obtained in grams is [Atomic mass of silver is $108$].

Match List-$I$ with List-$II$:

List-$I$ (Complex)	List-$II$ (Primary valency and Secondary valency)
$(A)$ $[Co(en)_2 Cl_2] Cl$	$(I)$ $3, 6$
$(B)$ $[Pt(NH_3)_2 Cl(NO_2)]$	$(II)$ $2, 4$
$(C)$ $Hg[Co(SCN)_4]$	$(III)$ $3, 4$
$(D)$ $[Mg(EDTA)]^{2-}$	$(IV)$ $2, 6$

Choose the correct answer from the options given below:

Consider the complex $[Co(NH_3)_4 CO_3]ClO_4$. The coordination number,oxidation number,and number of $d$-electrons on the metal are respectively: