NTA Abhyas NEET2020ChemistryChemical EquilibriumPractice
For the preparation of a buffer of p H = 8.26 , the amount of NH 4 2 SO 4 required to be mixed with one litre of 0.1 M N H 3 a q , p K b = 4.74 is ?
Options
- A1.0  moles
- B10.0   m o l e s
- C0.50   m o l e s
- D5  moles
Correct answer
C. 0.50   m o l e s
Step-by-step solution
pOH = pK b + log NH 4 + NH 3 5.74 = 4.74 + log NH 4 + 0.1 or log N H 4 + 0.1 = 1 or N H 4 + 0.1 = 10 or N H 4 + = 1 M ∴ NH 4 +   2 SO 4 required = 0.5  mole