For a chemical reaction, temperature is raised from 25° C to 35° C. The value of equilibrium constant, K_p is doubled . The heat of reaction ($\mathrm{\Delta }$H) for the reaction will be :

• 13.834 kcal

• 11.714 kcal

• 10.726 kcal

• 4.312 kcal

4.0 g molecular PCl₅ were heated in a vessel of 6 L volume. At equilibrium state , 50% of PCl₅ is dissociated. The equilibrium constant for the reaction is :

• 0.66 mol L^-1

• 0.33 mol L^-1

• 0.44 mol L^-1

• 0.88 mol L^-1

The pH of blood is :

• greater than 10

• less than 6

• greater than 7 and less than 8

• greater than 8 and less than 9

If K_b of HCN is 4.0 $\times$ 10^-10, then the pH of 2.5 $\times$ 10^-1 molar aqueous HCN is

• 2.0

• 4.7

• 5.0

• 2 x 10^-5

105.

H₃PO₃ is

• dibasic acid

• basic

• tribasic acid

• neutral

In an exothermic equilibrium ,

A + 3B $\rightleftharpoons$ AB₃

all the reactants and products are in gaseous state. The formation of AB₃ is favoured at :

• low temperature and low pressure

• low temperature and high pressure

• high temperature and high pressure

• high temperature and low pressure

A precipitate of AgCl is formed when equal volumes of the following are mixed :

[K_sp for AgCl = 10^-10]

• 10^-4 M AgNO₃ and 10^-7 M HCl

• 10^-5 M AgNO₃ and 10^-6 M HCl

• 10^-5 M AgNO₃ and 10^-4 M HCl

• 10^-6 M AgNO₃ and 10^-6 M HCl

The species among the following, which can act as an acid and a base is :

• HS${\mathrm{O}}_4^{2-}$

• S${\mathrm{O}}_4^{2-}$

• H₃O⁺

• Cl^-

If in the reaction N₂O₄ $\rightleftharpoons$ 2NO₂ , x is that part of N₂O₄ which dissociates, then the number of molecules at equilibrium will be :

• 1

• 3

• (1 + X)

• (1 + X)²

For the reaction, H₂ + I₂ $\rightleftharpoons$ 2HI, K = 47.6. If the initial number of moles of each reactant and product is 1 mole then at equilibrium

• [I₂] = [H₂] , [I₂] > [HI]

• [I₂] = [H₂] , [I₂] < [HI]

• [I₂] < [H₂] , [I₂] = [HI]

• [I₂] > [H₂] , [I₂] = [HI]