Dimethylamine, (CH₃)₂NH, is a weak molecular base with a value of 9.6 × 10^-4.for K_b. An aqueous solution contains 0.350 M (CH₃)₂NH and 0.250 M (CH₃)₂NH₂Cl per liter as the only solutes. If the K_sp of Mg(OH)₂ is 7.1 × 10^-12, what is the maximum [Mg²⁺] that can coexist with these solutes in the solution?Hint: Use the Henderson-Hasselbalch formula to find the pOH of the solution, and then use that to find [OH^-^].

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Quizplus · Accepted Answer

The pOH is calculated using the Henderson-Hasselbalch equation, resulting in a pOH of 3.96. This gives an [OH⁻] of 1.1 × 10⁻⁴ M. Using the Ksp expression for Mg(OH)₂, [Mg²⁺] = Ksp / [OH⁻]², we find [Mg²⁺] = 3.9 × 10⁻⁶ M.

Dimethylamine, (CH3)2NH, Is a Weak Molecular Base with a Value

Dimethylamine, (CH₃)₂NH, Is a Weak Molecular Base with a Value