A weak acid, HA, with a Ka of 1.0 × 10-5, has a partition coefficient, Kp, between water and an organic solvent of 1200. What restrictions on the sample's pH are necessary to ensure that a minimum of 99.9% of the weak acid is extracted in a single step from 50.0 mL of water using 50.0 mL of the organic solvent?​



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