19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Ka for HF is 3.5 × 10–4. Calculate Kb for the fluoride ion.
HCN is a weak acid (Ka = 6.2 × 10–10). NH4OH is a weak base (Kb = 1.8 × 10–5). A 1M solution of NH4CN would be :
A physician wishes to prepare a buffer solution at pH = 3.58 that efficiently resists a change in pH yet contains only small conc. of the buffering agents. Which one of the following weak acid together with its sodium…
The pH of blood does not appreciably change by a small addition of acid or a base because blood
How many moles of HCOONa must be added to 1L of 0.1 M HCOOH to prepare a buffer solution with a pH of 3.4 ? (Given : Ka for HCOOH = 2 × 10 –4); (10-0.3 = 0.5)
The dissociation constant of HCN is 5 × 10 –10. The pH of the solution prepared by mixing 1.5 mole of HCN and 0.15 moles of KCN in water and making up the total volume to 0.5 dm 3 is
In a mixture of a weak acid and its salt, the ratio of concentration of acid to salt is increased ten-fold. The pH of the solution
The pKa value of NH3 is 5. Calculate the pH of the buffer solution, 1 L of which contains 0.01 M NH4Cl and 0.10 M NH4OH
Consider the following solutions of equal concentrations. A = NH4Cl B = CH3COONa C = NH4OH D = CH3COOH A buffer solution can be obtained by mixing equal volumes of
Which of the following pairs constitutes a buffer?
Solution of 0.1 N NH4OH and 0.1 N NH4Cl has pH 9.25. The pKb of NH4OH is
A certain buffer solution contains equal concentration of X– and HX. the Ka for HX is 10–8. The pH of the buffer is
One litre of a buffer solution containing 0.01 M NH4Cl and 0.1 M NH4OH having pKb of 5 has pH of
A buffer solution of pH 9 can be prepared by mixing
The acidic buffer solution can be prepared by mixing solutions of
Buffer solution can be obtained by mixing aqueous solution of
A mixture of a weak acid (say acetic acid) and its salt with a strong base (say sodium acetate) is a buffer solution. Which other pair of substances from the following may have a similar property ?
A certain buffer solution contains equal concentration of Xand HX. The Kb for X is 10–10. The pH of the buffer is
Calculate the pH of a buffer prepared by mixing 0.10 mol of sodium formate and 0.05 mole of formic acid in 1.0 L of solution. [HCO2H : Ka =1.8 × 10–4]
What is the pH of a buffer solution which is 0.250 M in benzoic acid, C6H5COOH, and 0.150 M in sodium benzoate, C6H5COONa, if a K for benzoic acid is 6.5 × 10–5 ?
The principal buffer present in human blood is
For preparing a buffer solution of pH 6 by mixing sodium acetate and acetic acid, the ratio of the concentration of salt and acid should be (Ka = 10 –5)
The pKb of CNis 4.7. The pH of solution prepared by mixing 2.5 mol of KCN of 2.5 mol of HCN in water and making the total volume up to 500 mL is
10–6 M NaOH is diluted by 100 times. The pH of diluted base is
K C K /C x xx a H