Morphine, C₁₇H₁₉NO₃, is often used to control severe post-operative pain.What is the pH of the solution made by dissolving 25.0 mg of morphine in 100.mL of water? (For morphine, K_b = 1.62 × 10^-6.) A)9.57 B)9.08 C)3.79 D)9.87 E)4.43

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Morphine is a weak base, so the pH of the solution will be greater than 7. The Kb value for morphine is 1.62 × 10^-6, so the pKb is 5.79. The pH of the solution can be calculated using the following equation:pH = 14 - pKb - log([HB+]/[B])where [HB+] is the concentration of the conjugate acid of morphine and [B] is the concentration of morphine.The concentration of morphine in the solution is:25.0 mg / (100 mL * 1 g/mL * 1000 mg/g) = 2.50 × 10^-4 MThe concentration of the conjugate acid of morphine can be calculated using the following equation:Kb = [HB+][OH-]/[B][HB+] = Kb[B]/[OH-][HB+] = (1.62 × 10^-6)(2.50 × 10^-4 M)/(1.0 × 10^-7 M) = 4.05 × 10^-3 MThe pH of the solution is:pH = 14 - 5.79 - log(4.05 × 10^-3 M/2.50 × 10^-4 M) = 9.57

Morphine, C17H19NO3, Is Often Used to Control Severe Post-Operative Pain

Morphine, C₁₇H₁₉NO₃, Is Often Used to Control Severe Post-Operative Pain