AIIMS 2018 Chemistry Buffer Solutions MCQ Question

Option A is correct because the calculation of pH from pOH shows that pH = 14 - pOH = 14 - 4.15 = 9.85, indicating a basic solution formed by the reaction of NH₃ (a weak base) with HCl (a strong acid) to produce NH₄Cl. Other options are incorrect as they do not reflect the calculated pH; option B (pH = 4.15) suggests an acidic solution, which is inconsistent with the basic nature of the resulting solution, while options C (pH = 7) and D (pH = 10) do not match the derived pH value from the pOH calculation. Understanding the relationship between pH and pOH is crucial, as it allows for the determination of acidity or basicity in solutions.