421.

When one mole of A and one mole of B were heated in one litre flask at T(K), 0.5 mole of C was formed in the equilibrium,  A + B $\rightleftharpoons$ C + D the equilibrium constant, K_c is

• 0.25

• 0.5

• 1

• 2

If the solubility of Ca₃(PO₄)₂ in water is x mol L^-1, its solubility product in mol⁵L^-5 is

• 6x⁵

• 36x⁵

• 64x⁵

• 108x⁵

The buffer system which helps to maintain the pH of blood between 7.26 to 7.42, is

• H₂CO₃ /HCO${}_3^{-}$

• NH₄OH/ NH₄Cl

• CH₃COOH/ CH₃COO^-

• CH₃COONH₄

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

Identify the Bronsted acid in the following equation

${\mathrm{PO}}_4^{3-} + {\mathrm{H}}_2\mathrm{O}\hspace{0.17em}\left(\mathrm{l}\right) \to {\mathrm{HPO}}_4^{2-} \left(\mathrm{aq}\right) + {\mathrm{OH}}^{-} \left(\mathrm{aq}\right)$

• PO${}_4^{3-}$

• HPO₄

• H₂O

• OH^-

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)

If solubility product of Zr₃(PO₄)₄ is denoted by K_sp and its molar solubility is denoted by S, then which of the following relation between S and K_sp is correct ?

• S = ${\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{6912}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$7$}\right.}$

• S = ${\left(\frac{{\mathrm{K}}_{\mathrm{SP}}}{929}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$9$}\right.}$

• S = ${\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{144}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$6$}\right.}$

• S = ${\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{216}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$7$}\right.}$