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

• Base	Acid	End Point
  Strong	Strong	Pink to colourless

• Base	Acid	End Point
  Weak	Strong	Colourless to pink

• Base	Acid	End Point
  Strong	Strong	Pinkish Red to Yellow

• Base	Acid	End Point
  Weak	Strong	Yellow to Pinkish Red

The predominant form of histamine present in human blood is (pKa, Histidine = 6.0)

Which of the following are Lewis acids?

• BCl₃ and AlCl₃

• PH₃ and BCl₃

• AlCl₃ and SiCl₄

• PH₃ and SiCl₄

34.

Dissolving NaCN in de-ionised water will result in a solution having

• pH < 7

• pH = 7

• pOH = 7

• pH > 7

PbCl₂ is insoluble in cold water. Addition of HCl increases its solubility due to

• formation of soluble complex anions like [PbCl₃]^-

• oxidation of Pb(II) to PB(IV)

• formation of [Pb(H₂O)₆]²⁺

• formation of polymeric lead complexes

Of the following compounds, which one is the strongest Bronsted acid in a aqueous solution?

• HClO₃

• HClO₂

• HOCl

• HOBr

The yield of acetanilide in the reaction (100% conversion) of 2 moles of aniline with 1 mole of acetic anhydride is

• 270 gm

• 135 gm

• 67.5 gm

• 177 gm

Equilibrium constants for the following reactions at 1200 K are given

2H₂O (g) $\rightleftharpoons$ 2H₂ (g) + O₂ (g)    [K₁ = 6.8 × 10^-8]

2CO₂ (g) $\rightleftharpoons$ 2CO (g) + O₂ (g)    [K₂ = 1.6 × 10^-6]

The equilibrium constant for the reaction?

H₂(g) + CO₂(g) $\rightleftharpoons$ CO (g) + H₂O (g)

at 1200 K will be

• 0.05

• 20

• 0.2

• 5.0

Which of the following solutions will turn violet when a drop of lime juice is added to it?

• A solution of NaI

• A solution mixture of KI and NaIO₃

• A solution mixture of NaI and KI

• A solution mixture of KIO₃ and NaIO₃

The molar solubility (in mol L^-1) of a sparingly soluble salt MX₄ is 'S'. The corresponding solubility product is K_sp in terms of 'K_sp' is given by the relation

• $\mathrm{S}={\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{128}\right)}^{1/4}$

• $\mathrm{S}={\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{256}\right)}^{1/5}$

• S=(256 K_sp)^1/5

• S=(128 K_sp)^1/4