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

An alkali is titrated against an acid with methyl orange as indicator, which of the following is a correct combination?

The correct match between items of List-I and List-II is :

List - I		List - II
(A)	Coloured impurity	(P)	Steam distribution
(B)	Mixture of o-nitrophenol and p-nitrophenol	(Q)	Fractional distribution
(C)	Crude Naphtha	(R)	Charcoal treatment
(d)	Mixture of glycerol and sugars	(S)	Distillation under reduced pressure

A solution containing a group-IV cation gives a precipitate on passing H₂S. A solution of this precipitate in dil.HCl produces a white precipitate with NaOH solution and bluish-white precipitate with basic potassium ferrocyanide. The cation is :