$A$ coordination compound has the formula $MCl_3 \cdot 4H_2O$. The coordination number of the metal is $6$,and it contains no water of hydration. How many $ml$ of $0.1 \, M \, AgNO_3$ are required to precipitate the chloride ions from $200 \, ml$ of a $0.01 \, M$ solution of this compound?

Match each coordination compound in List-$I$ with an appropriate pair of characteristics from List-$II$ and select the correct answer using the code given below the lists.
$\{ en = H_2NCH_2CH_2NH_2 \}$; atomic numbers: $\{Ti = 22; Cr = 24; Co = 27; Pt = 78\}$

List-$I$	List-$II$
$P.$ $[Cr(NH_3)_4Cl_2]Cl$	$1.$ Paramagnetic and exhibits ionisation isomerism
$Q.$ $[Ti(H_2O)_5Cl](NO_3)_2$	$2.$ Diamagnetic and exhibits cis-trans isomerism
$R.$ $[Pt(en)(NH_3)_2Cl_2]NO_3$	$3.$ Paramagnetic and exhibits cis-trans isomerism
$S.$ $[Co(NH_3)_4(NO_3)_2]NO_3$	$4.$ Diamagnetic and exhibits ionisation isomerism
Codes: $P, Q, R, S$

When potassium iodide is added to an aqueous solution of potassium ferricyanide,a reversible reaction is observed in which a complex $P$ is formed. In a strong acidic medium,the equilibrium shifts completely towards $P$. Addition of zinc chloride to $P$ in a slightly acidic medium results in a sparingly soluble complex $Q$.
$(1)$ The number of moles of potassium iodide required to produce two moles of $P$ is. . .
$(2)$ The number of zinc ions present in the molecular formula of $Q$ is. . . .
Give the answer for $(1)$ and $(2)$.

The aqueous solution of $CuCrO_4$ is green because it contains

The ammonia prepared by treating ammonium sulphate with calcium hydroxide is completely used by $NiCl_2 \cdot 6H_2O$ to form a stable coordination compound. Assume that both the reactions are $100 \%$ complete. If $1584 \ g$ of ammonium sulphate and $952 \ g$ of $NiCl_2 \cdot 6H_2O$ are used in the preparation,the combined weight (in grams) of gypsum and the nickel-ammonia coordination compound thus produced is $\qquad$ (Atomic weights in $g \ mol^{-1}: H=1, N=14, O=16, S=32, Cl=35.5, Ca=40, Ni=59$)

The complex ion $[Co(en)_2Br_2]^+$ has two optical isomers. Their correct configurations are: