Chapter 2, Problem 55P

The ammonium ion (pKa = 9.25) has a lower pKa than the methyl ammonium ion (pKa = 10.66). Explain which of the two species is the stronger base

Another way to express acid strength is by using pk b:pK a =−logK a Another way to express base strength is by using pK b pK b =−logK b A new potential heart medicine, code-named X-281, is being tested by a pharmaceutical company, Pharma-pill. As a research technician at Pharma-pill, you are told that X-281 is a monoprotic weak acid, but because of security concerns, the actual chemical formula must remain top secret. The company is interested in the drug's K a value because only the dissociated form of the chemical is active in preventing cholesterol buildup in arteries.To find the pK a of X-281, you prepare a 0.079 M M test solution of X-281 at 25.0 ∘ C The pH of the solution is determined to be 3.00. What is the pK a of X-281?

NaHCO3 can deprotonate benzoic acid but cannot deprotonate phenol. On the other hand, NaOH can deprotonate both benzoic acid and phenol. Given this information, rank the molecules numbered I to V in order of decreasing acidity. COH cOH он H,0 H,CO, IV CH3 II I II (A) V > II >I > III > IV (В) II > 1 > V > III IV (C) II > V >I > IV > II