Equilibrium

Which one of the following is correct?

• The equilibrium constant (K_c) is independent of temperature

• The value of K_c is independent of initial concentrations of reactants and products

• At equilibrium, the rate of the forward reaction is twice the rate of the backward reaction.

• The equilibrium constant (K_c) for the reaction

  $\mathrm{Ni}\left(\mathrm{s}\right) + 4\mathrm{CO}\left(\mathrm{g}\right) \rightleftharpoons \mathrm{Ni}\left(\mathrm{CO}{)}_4\right(\mathrm{g}) \mathrm{is}, \frac{\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]}{\left[\mathrm{CO}\right]}$

pH of an aqueous solution of NH₄Cl is

• 7

• >7

• <7

• 1

Which of the following statement is correct ?

• BCl₃ and AlCl₃ are both Lewis acids and AlCl₃ is stronger than BCl₃

• BCl₃ and AlCl₃ are both equally strong Lewis acid

• Both BCl₃ and AlCl₃ are not Lewis acid

• BCl₃ and AlCl₃ are both Lewis acids and BCl₃ is stronger than AlCl₃

For the reaction, 2HI (g) $\rightleftharpoons$H₂ (g) + I₂ (g) the degree of dissociation (α) of HI (g) is related to equilibrium constant K_p by the expression

• $\sqrt{\frac{1 + 2{\mathrm{K}}_{\mathrm{p}}}{2}}$

• $\sqrt{\frac{2{\mathrm{K}}_{\mathrm{p}}}{1+ 2{\mathrm{K}}_{\mathrm{p}}}}$

• $\frac{2\sqrt{{\mathrm{K}}_{\mathrm{p}}}}{1 + 2\sqrt{{\mathrm{K}}_{\mathrm{p}}}}$

• $\frac{1 + 2\sqrt{{\mathrm{K}}_{\mathrm{p}}}}{2}$

Rank the following in decreasing order of basic strength

(i) CH₃-CH₂-C≡C^-

(ii) CH₃-CH₂-S^-

(iii) CH₃-CH₂-CO${}_2^{-}$

(iv) CH₃-CH₂-O^-

• (iv) > (i) > (ii) > (iii)

• (i) > (iv) > (ii) > (iii)

• (i) > (iv) > (iii) > (ii)

• (ii) > (i) > (iv) > (iii)

In the following compounds, the decreasing order of basic strength will be:

• (C₂H₅)₂NH > NH₃ > C₂H₅NH₂

• (C₂H₅)₂NH > C₂H₅NH₂ > NH₃

• C₂H₅NH₂ > NH₃ > (C₂H₅)₂NH

• NH₃ > C₂H₅NH₂ > (C₂H₅)₂NH

For the following reactions, equilibrium constans are given:

S(s) + O₂(g) $\rightleftharpoons$SO₂(g); K₁ = 10⁵²

2S(s) + 3O₂(g) $\rightleftharpoons \; 2$SO₃(g); K₂ = 10¹²⁹

The equilibrium constant for the reaction,

2SO₂(s) + O₂(g) $\rightleftharpoons \; 2$SO₃(g)

• 10¹⁸¹

• 10⁷⁷

• 10¹⁵⁴

• 10²⁵

In an acid-base titration, 0.1 M HCl solution was added to the NaOH solution of unknown strength. Which of the following correctly shows the change of pH of the titration mixture in this experiment ?

• (D)

• (A)

• (C)

• (B)

Consider the following statements

a) The pH of a mixture containing 400mL of 0.1M H2SO4 and 400 mLof 0.1M NaOH will be approximately 1.3.

b) Ionic product of water is temperature dependent.

c) A monobasic acid with Ka=10^-5 has a pH=5. The degree of dissociation of this acid is 50%.

d) The Le Chatelier’s Principle is not applicable to common-ion effect.

The correct statements are

• b and c

• a,b and d

• a,b, and c

• a and b

The pH of a 0.02 M NH₄Cl solution will be: [ given K_b(NH₄OH) = 10^-5 and log 2= 0.301]

• 5.35

• 2.65

• 4.65

• 4.35