system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
pKa is the pH at which:
assistant
The correct answer is  Ans. B. 50 percent of the drug is ionized50 percent of the drug is ionizeda. Drugs are weak acids or basesb. Their ionization depends on pH of solution and pKa of drug (pH at which a drug is 50% ionized)c. Acidic drugs ionize at basic pH while basic drugs ionize more at acidic pHd. One-unit change in pH from pKa causes ten times change in ionization