Calculate the pH of a 1.00 L solution of 0.100 M NH₃(aq) after the addition of 0.010 mol HCl(g). For NH₃, pKb = 4.74. A) 10.21 B) 9.26 C) 8.31 D) 11.46

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The correct answer is A because the addition of HCl(g) will react with NH3(aq) to form NH4Cl(aq), which will lower the pH of the solution. The pH of the solution can be calculated using the Henderson-Hasselbalch equation:pH = pKb + log([A-]/[HA])where [A-] is the concentration of the conjugate base (NH2-) and [HA] is the concentration of the weak acid (NH3).In this case, the initial concentration of NH3 is 0.100 M and the initial concentration of NH4Cl is 0.000 M. After the addition of 0.010 mol HCl(g), the concentration of NH4Cl will increase to 0.010 M and the concentration of NH3 will decrease to 0.090 M.Substituting these values into the Henderson-Hasselbalch equation, we get:pH = 4.74 + log([0.010]/[0.090]) = 10.21Therefore, the pH of the solution after the addition of HCl(g) is 10.21.

Calculate the PH of a 1