For NH₃,pK_b = 4.74.What is the pH of an aqueous buffer solution that is 0.050 M NH₃(aq)and 0.20 M NH₄Cl(aq)?

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Quizplus · Accepted Answer

The pH of a buffer solution can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log([base]/[acid]). First, calculate pKa from pKb: pKa = 14 - pKb = 14 - 4.74 = 9.26. Then, apply the equation: pH = 9.26 + log(0.050/0.20) = 9.26 + log(0.25) = 9.26 - 0.60 = 8.66.

For NH3,pKb = 4

For NH₃,pK_b = 4