Buffer solution among the following options is :           

1. HNO₂ and NaNO₂           

2. NaOH and NaCl

3. HNO₃ and NH₄NO₃         

4. HCl and KCl

According to Le-Chatelier's principle, adding heat to a solid $\rightleftharpoons$liquid equilibrium will cause the :

1. Temperature to increase

2. Temperature to decrease

3. Amount of liquid to decrease

4. Amount of solid to decrease

Ostwald's solution dilution law is applicable in the case of the solution of:

1. CH₃COOH                                     

2. NaCl

3. NaOH                                           

4. H₂SO₄

The pK_a of acetylsalicylic acid (aspirin) is 3.5. The pH of gastric juice in the human stomach is about 2-3 and the pH in the small intestine is about 8. Aspirin will be:

1. Unionized in the small intestine and in the stomach

2. Completely ionized in the small intestine and in the stomach

3. Ionized in the stomach and almost unionized in the small intestine

4. Ionized in the small intestine and almost unionized in the stomach

What is [H⁺] in mol/L of a solution that is 0.20 M in CH₃COONa and 0.10 M in CH₃COOH?

(K_a for CH₃COOH = 1.8 x 10^-5)       

1. 3.5x10^-4           

2. 1.1x10^-5

3. 1.8x10^-5           

4. 9.0x10^-6

The hydrolysis of the salt of a strong acid and a weak base is called:

1. Anionic hydrolysis

2. Cationic hydrolysis

3. Amphoteric hydrolysis

4. None of the above

For the reaction, A+B $\rightleftharpoons$3C at 25$°$ C, a 3 litre vessel contains 1, 2, and 4 mole of A, B and C respectively. If K_c for the reaction is 10, then the reaction will proceed in:

1. forward direction                           

2. backward direction

3. in either direction                           

4. in equilibrium

The pH of 0.1M soution of the folowing salts increases in the order:

1. NaCl < NH₄Cl < NaCN < HCl

2. HCl < NH₄Cl < NaCl < NaCN

3. NaCN < NH₄Cl < NaCl < HCl

4. HCl < NaCl < NaCN < NH₄Cl 

Three reactions involving ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$ are given below:

(i) H₃PO₄ + H₂O $\to$H₃O⁺ + ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$

(ii) ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$ + H₂O $\to$${\mathrm{HPO}}_4^{2-}$ + H₃O⁺

(iii) ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$ + OH^- $\to$H₃PO₄ +O^2-

In which of the above does ${\mathrm{H}}_2{\mathrm{PO}}_4^{-}$ act as an acid?

1. (i) only                                 

2. (ii) only

3. (i) and (ii)                           

4. (iii) only

Which of the following is most soluble in water?

1. MnS (K_sp = 8x10^-37)         

2. ZnS (K_sp = 7x10^-16)

3. Bi₂S₃ (K_sp = 1x10^-70)       

4. Ag₂S (K_sp = 6x10^-51)