The equilibrium constant at 298 K for a reaction A+B ⇌ C+D is 100. If the initial concentration of all the four species were 1 M each, then equilibrium concentration of D (in mol L⁻¹ ) will be:

• 0.818

• 1.818

• 1.182

• 1.182

For the reaction,


if K_p = K_c (RT)^x where the symbol has usual meaning then the value of x is (assuming ideality)

• -1

• -1/2

• 1/2

• 1/2

The species which can best serve as an initiator for the cationic polymerization is

• LiAlH₄

• HNO₃

• AlCl₃

• AlCl₃

The equilibrium constant (Kc) for the reaction, N₂(g) + O₂ (g) → 2NO (g) at temperature T is 4 x 10-4. The value of Kc for the reaction  at the same temperature is

• 0.02

• 2.5 x 10²

• 4 x 10^-4

• 4 x 10^-4

The pH of a 0.1 molar solution of the acid HQ is 3. The value of the ionisation constant, K_a of this acid is

• 3 x 10^–1

• 1 x 10^–3

• 1 x 10^—5

• 1 x 10^—5

Consider the reaction:
Cl₂(aq) + H₂S(aq) → S (s) + 2H⁺ (aq) + 2Cl^- (aq)
The rate equation for this reaction is
I. Cl₂ + H₂S → H⁺ +Cl^- + Cl⁺ +HS^-
II. H₂S ⇌ H⁺ + HS^- (fast equilibrium)
Cl₂ + HS^- → 2Cl^- + H⁺ + S (slow)

• II only

• Both (I) and (II)

• Neither (I) nor (II)

• Neither (I) nor (II)

7.

Three reactions involving H₂PO₄^- are given below
I. H₃PO₄ + H₂O → H₃O⁺ + H₂PO₄^-
II. H₂PO₄^- + H₂O→ HPO₄^2- + H₃O⁺
III. H₂PO₄^- + OH^- → H₃PO₄  + O^2-
In which of the above does H₂PO₄^- act  as an acid

• (II) only

• (I) and (II)

• (III) only

• (III) only

In aqueous solution the ionization constants for carbonic acid are
K₁ = 4.2 x 10^-7 and K₂ = 4.8 x 10^-11.
Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

• The concentration of CO₃^2- is 0.034 M

• The concentration of CO₃^2- is greater than that of HCO₃^-

• The concentration of H⁺ and HCO₃^- are approximately equal

• The concentration of H⁺ and HCO₃^- are approximately equal

The correct order of increasing basicity of the given conjugate bases (R = CH₃) is

At 25°C, the solubility product of Mg(OH)₂ is 1.0 × 10^–11. At which pH, will Mg²⁺ ions start precipitating in the form of Mg(OH)₂ from a solution of 0.001 M Mg²⁺ ions?

• 9

• 10

• 11

• 11