Buffer Solutions
Trending Questions
Q.
What is meant by buffer solutions?
Q.
Give Two Examples For Acidic Buffer.
Q.
Why are buffers weak acids and bases?
Q.
pH of a buffer solution varies with_________.
Q.
An acid is a compound which, when dissolved in water, gives ___ ions as the only ___ions.
Q. The species: H2O, HCO−3, HSO−4 and NH3 can act both as Bronsted acids and bases. For each case give the corresponding conjugate acid and base.
Q. Which one of the following is correct for salt buffer ?
- A solution of the salt of weak acid and weak base in water.
- A solution of the salt of strong acid and weak base in water.
- A solution of the salt of weak acid and strong base in water.
- None of the above
Q. Which of the following will form a buffer solution?
(a) CH3COONa+CH3COOH
(b) NaCl+NaOH
(c) NH4Cl+NH4OH
(d) Na2SO4+H2SO4
(a) CH3COONa+CH3COOH
(b) NaCl+NaOH
(c) NH4Cl+NH4OH
(d) Na2SO4+H2SO4
- A, B
- B, C
- A, C
- A, D
Q. Which one is incorrect regarding the representation of buffer index ?
- [Conjugate base][Weak Acid]<0.1
- [Conjugate acid][Weak Base]<10
- [Conjugate base][Weak Acid]>0.1
- None of the above
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.
Which of the following is not a buffer solution?
Ammonium chloride + ammonium hydroxide
Sodium acetate + acetic acid
NaOH + HCl
Sodium formate + formic acid
Q. Total numbers of buffers can be made by reaction of H3PO4 and NaOH is
- 3
- 1
- 4
- 2
Q. If 0.01 mole of NaOH is added to 1 litre solution of a basic buffer having pH=8.7 initially, the pH changes to 9. Calculate the buffer capacity of the buffer.
- 0.33
- 0.033
- 0.087
- 0.02
Q. Aqueous solution of HNO3, KOH, CH3COOH and CH3COONa of identical concentration are provided. The pair(s) of solution which forms buffer upon mixing is (are)
- HNO3 and CH3COOH
- KOH and CH3COONa
- HNO3 and CH3COONa
- CH3COOH and CH3COONa
Q. Buffer capacity of abuffer solution is x, the volume on M NaOH added to 100 mL of this solution if change the pH by is:
- 0.1xmL
- 10xmL
- 100xmL
- xmL
Q. Predict if the solutions of the following salts are neutral, acidic or basic:
NaCl, KBr, NaCN, NH4NO3 and KF
NaCl, KBr, NaCN, NH4NO3 and KF
Q. When 0.002 mol of acid is added to 250 mL of a buffer solution, pH decreaes by 0.02 units.
The buffer capacity of the system is:
- 0.1
- 0.2
- 0.3
- 0.4
Q. 20 mL of 0.1 M H2SO4 solution is added to 30 mL of 0.2 M NH4OH solution. The pH of the resultant mixture is [pKb of NH4OH=4.7, log2=0.3010]
- 5.2
- 9
- 5
- 9.4
Q. What is meant by the conjugate acid-base pair? Find the conjugate acid/base for the following species.
HNO2, CN−, HClO4F−, OH−, CO2−3 and S2−
HNO2, CN−, HClO4F−, OH−, CO2−3 and S2−
Q. Which one of the following is salt buffer ?
- (NH4CN) solution
- (CH3COONH4, ) solution
- (a) and (b) above.
- None of the above
Q. Consider N3- O2- F- Na+ Mg2+ and Al3+ (a) what is common in them (b) arrange them in a order of increasing ionic radii
Q. When 36.5 g of HCl is added to 1 L of an acidic buffer solution, its pH changes from 4 to 3. The buffer capacity of the buffer is:
- 1
- 2
- 3
- 4
Q. 5 moles of an acid is required to change the pH of 1 litre of buffer by 2 units. The buffer capacity of the solution is:
- 5
- 3.5
- 15
- 2.5
Q. What among the following solutions will be the most efficient buffer?
- 0.1M CH3COONa+0.01M CH3COOH
- 0.1M NH4Cl+0.1M NH4OH
- 0.001M HCOOH+0.002M HCOONa
- All of the above
Q. Select the wrong statement about buffer capacity (β) when CBOH and CHA represents the number of mole of strong base or strong acid added to 1 litre of buffer mixture.
- β=dCBOHdpH
- β=−dCHAdpH
- Buffer capacity is satisfactory over a pH range of pKa±1
- In a buffer mixture, the salt is also hydrolysed to produce acid or base and thereby to influence buffer capacity
Q. Which of the following solutions will alter the pH of the solution on dilution?
- 0.1M NH4OH+0.1M NH4Cl
- 0.5M H2CO3+0.5M NaHCO3
- 1M CH3COONH4
- 0.1M CH3COONa
