What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M NH₃ with 20.00 mL of 0.10 M NH₄Cl? Assume that the volume of the solutions are additive and that K_b = 1.8 × 10^-5for NH₃. A)8.86 B)10.26 C)9.65 D)11.13

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First, calculate the number of moles of each solution: n1 = 0.050 L x 0.10 mol/L = 0.005 mol n2 = 0.020 L x 0.10 mol/L = 0.002 mol Next, calculate the total number of moles and the concentration of the resulting solution: ntotal = n1 + n2 = 0.007 mol Ctotal = ntotal / (0.050 L + 0.020 L) = 0.077 mol/L Next, calculate the pOH using the concentration of OH- ions from the dissociation of NH₃: [OH-] = K_b / [H+] = 1.8 x 10^-5 / 0.077 mol/L = 2.34 x 10^-4 pOH = -log[OH-] = 3.63 Finally, calculate the pH: pH + pOH = 14.00 pH = 14.00 - pOH = 10.37 Therefore, the closest answer choice is C) 9.65.

What Is the PH of a Solution Prepared by Mixing