Which of the following is a Lewis acid ?

• OH^-

• H⁺

• F^-

• NH₃

512.

Which of the following is correct?

• The pH of one litre solution containing 0.49 g of H₂SO₄ is 2.0

• The conjugate base of H₂S is S^2-

• BF₃ is a Lewis base

• Phenolphthalein is colourless in basic medium

Which of the following is correct ?

• Catalyst undergoes permanent chemical change

• Particle size of solute in true solution is 10^-3 m

• Starch solution is a hydrosol

• Hydrolysis of liquid ester in the presence of mineral acid is an example of heterogeneous catalysis reactions

What is the equation for the equilibrium constant (Kc) for the following reaction?

$\frac{1}{2}\mathrm{A}\left(\mathrm{g}\right) + \frac{1}{3}\mathrm{B}\left(\mathrm{g}\right) \stackrel{\mathrm{T}\left(\mathrm{K}\right)}{\rightleftharpoons } \frac{2}{3}\mathrm{C}\left(\mathrm{g}\right)$

• ${\mathrm{K}}_{\mathrm{c}} = \frac{{\left[\mathrm{A}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2 $}\right.}}{\left[\mathrm{B}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}}}{{\left[\mathrm{C}\right]}^{{\displaystyle \raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}}}$

• ${\mathrm{K}}_{\mathrm{c}} = \frac{{\left[\mathrm{C}\right]}^{{\displaystyle \raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}}}{{\left[\mathrm{A}\right]}^{2 }{\left[\mathrm{B}\right]}^3}$

• ${\mathrm{K}}_{\mathrm{c}} = \frac{{\left[\mathrm{C}\right]}^{{\displaystyle \raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}}}{{\left[\mathrm{A}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}}{\left[\mathrm{B}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}}}$

• ${\mathrm{K}}_{\mathrm{c}} = \frac{{\left[\mathrm{C}\right]}^{{\displaystyle \raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}}}{{\left[\mathrm{A}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}}+{\left[\mathrm{B}\right]}^{{\displaystyle \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right.}}}$

A 0.1 aqueous solution of a weak acid is 2% ionised. If the ionic product of water is 1 x 10^-4, the [OH^-] is

• 5 x 10^-12 M

• 2 x 10^-3 M

• 1 x 10^-14 M

• None of these

Disperse phase and dispersion medium in butter are respectively

• solid and liquid

• liquid and solid

• liquid and liquid

• solid and solid

9.2 g N₂O₄ is heated in a 1L vessel till equilibrium state is established

N₂O₄ (g) $\rightleftharpoons$ 2NO₂ (g)

In equilibrium state 50% Np4 was dissociated, equilibrium constant will be (mol. wt. of N₂O₄ = 92)

• 0.1

• 0.4

• 0.3

• 0.2

Solubility product of PbCl₂ at 298 K is 1 x 10^-6. At this temperature solubility of PbCl₂ in mol/L is

• (1 x 10^-6)^1/2

• (1 x 10^-6)^1/3

• (0.25 x 10^-6)^1/3

• (2.5 x 10^-6)^1/2

Which of the following is the electron deficient molecule?

• B₂H₆

• C₂H₆

• PH₃

• SiH₄

Equilibrium constants K₁ and K₂ for the following equilibria
NO (g) + $\frac{1}{2}{\mathrm{O}}_2$ $\stackrel{{\mathrm{K}}_1}{\rightleftharpoons }$ NO₂(g) and

2NO₂(g) $\stackrel{{\mathrm{K}}_2}{\rightleftharpoons }$ 2NO (g) + O₂(g)

are related as

• ${\mathrm{K}}_2 = \frac{1 }{{\mathrm{K}}_1}$

• ${\mathrm{K}}_2 = {\mathrm{K}}_1^2$

• ${\mathrm{K}}_2 = \frac{{\mathrm{K}}_1}{2}$

• ${\mathrm{K}}_2 =\frac{1}{{\mathrm{K}}_1^2}$