Buffer Solutions
Trending Questions
Q. pKb for NH4OH at certain temperature is 4.74. The pH of basic buffer containing equimolar concentration of NH4OH and NH4Cl will be :
- 9.26
- 4.74
- 7.74
- 2.37
Q. Which of the following can be used as a buffer solution?
A solution containing NaCl and NaOH.
A solution containing NaCl and NH4OH.
A solution containing sodium acetate.
A solution containing ammonium acetate.
Q. Aqueous solutions of HNO3, KOH, CH3COOH and CH3COONa of identical concentrations are provided. The pair(s) of solutions which form a buffer upon mixing is (are)
- HNO3 and CH3COOH
- KOH and CH3COONa
- HNO3 and CH3COONa
- CH3COOH and CH3COONa
Q.
Which of the following is not a buffer solution?
Ammonium chloride + ammonium hydroxide
Sodium acetate + acetic acid
NaOH + HCl
Sodium formate + formic acid
Q.
On the addition of a small amount of an acid or a base, the pH value of a buffer solution:
decreases
remains unaltered
increases
none of these
Q. If a buffer solution of 2, 4-dinitrophenol has a pH of 5, what is the ratio of dissociated to undissociated molecules of 2, 4-dinitrophenol in the solution? (pKa of 2, 4-dinitrophenol = 4)
- 10
Q. 0.1 mole arsenic acid (H3AsO4) is dissolved in a 1L buffer solution of pH=8. Which of the following options is/are correct? For arsenic acid: Ka1=2.5×10−4, Ka2=5×10−8, Ka3=2×10−13.
(‘<<’ sign denotes that the higher concentration is 100 times greater than the lower one or more)
(‘<<’ sign denotes that the higher concentration is 100 times greater than the lower one or more)
- [H3AsO4]<<[H2AsO−4]
- [H2AsO−4]<<[HAsO2−4]
- [HAsO2−4]<<[H2AsO−4]
- [AsO3−4]<<[HAsO2−4]
Q. A buffer solution that has a pH of 4.72 is prepared by mixing of 1 M NaOH and 1M HCN. What is the ratio of volumes of the acid to the base? (pKb of CN−=9.28)
- 1 : 1
- 1 : 2
- 2 : 1
- 3 : 1
Q. Ionisation constant of benzoic acid is 6×10−5 and Ksp of silver benzoate is 2.5×10−13 . How many times is the salt more soluble in a buffer of pH of 4 as compared to its solubility in pure water?
(Given:√23=0.82)
(Given:√23=0.82)
Q. Which of the following solutions will alter the pH of the solution on dilution?
- 0.1M CH3COONa
- 0.5M H2CO3+0.5M NaHCO3
- 1M CH3COONH4
- 0.1M NH4OH+0.1M NH4Cl