351.

The pair of compound which cannot exist together in solution is

• NaHCO₃ and NaOH

• NaHCO₃ and H₂O

• NaHCO₃ and Na₂CO₃

• Na₂CO₃ and NaOH

Which is most basic in character ?

• CsOH

• KOH

• NaOH

• LiOH

Would gaseous HCl be considered as an Arrhenius acid ?

• Yes

• No

• Not known

• Gaseous HCl does not exist

The degree of hydrolysis in hydrolytic equilibrium

A^- + H₂O $\rightleftharpoons$ HZ + OH^-

at salt concentration of 0.001 M is :

(K_a = 1 × 10^-5)

• 1 × 10^-3

• 1 × 10^-4

• 5 × 10^-4

• 1 × 10^-6

The reaction quotient 'Q' is useful in predicting the direction of the reaction. Which of the following is incorrect?

• If Q_c < K_c, the forward reaction is favoured

• If Q_c > K_c, the forward reaction is favoured

• If Q_c >K_c, the forward reaction is favoured and Q_c =K_c, no reaction occur.

• None of these

pH of 1M NH₃ aqueous solution is (K_b = 1.8 × 10^-5)

• 11.13

• 12.5

• 13.42

• 11.55

Equivalent weight of an acid :

• depends on the reaction involved

• depends upon the number of oxygen atoms present

• is always constant

• None of the above

Two moles of PCl₅ were heated in a closed vessel of 2 L. At equilibrium, 40% of PCl₅ is dissociated into PCl₃ and Cl₃. The value of equilibrium constant is :

• 0.53

• 0.267

• 2.63

• 5.3

The solubility product of Barium sulphate is 1.5 × 10^-9 at 18°C. Its solubility in water at 18°C is :

• 1.5 × 10^-9

• 1.5 × 10^-5

• 3.9 × 10^-9

• 3.9 × 10^-5

pH scale was introduced by :

• Arrhenius

• Sorensen

• Lewis

• Lowry