Question

1. A strong acid would have a pKa: a. greater than 12. b. less than 2. 2. The major number of drugs available today would be classified as: a. proton donors b. proton acceptors A pharmacist must understand the definition of acids/bases. The BRÖNSTED-LOWREY model defines an acid as a proton (H') donor and a base as a proton (H*) acceptor. Recognition of a non-ionized drug as an acid or a base is necessary to calculate its percent ionization. When a drug's pKa is not available, a drug may be identified as an acid or a base by using its name or based on its salt form. This can also be helpful when a pKa is known but the drug's chemical structure is not readily available. For each of the drug names or salt forms provided, indicate whether it is an acid or a base according to the BRÖNSTED-LOWREY model definition 3. Lidocaine HC a. acid b. base 4. Cefuroxime Sodium a. acid b.base

Answer 1

1. less than 2, stronger the acid lower the pka value, pka is a dissociation constant of hydrogen ions therefore, stronger the acid, lower the pka value.

2 Majority of drugs are weak acids or weak bases so it can accept or donate proton

3.acid, lidocaine is a weak base, when the weak base is combined with strong acid it becomes acidic

4.base, cefuroxime sodium is a salt so it is basic in nature