Which of the following is a Lewis acid ?

• OH^-

• H⁺

• F^-

• NH₃

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

514.

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

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

• ${\mathrm{K}}_2 = {\mathrm{K}}_1^2$

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

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