Codeine is a weak organic base with a Kb = 1.6 x 10-6 C18H21NO3(aq) + H2O(l) ⇌ C18H21NO3H+(aq) + OH-(aq)

a) What is the value of pKa and pKb?
b) Calculate the equilibrium concentrations for [C18H21NO3(aq)], [C18H21NO3H+(aq)], and [OH-(aq)] for a 0.050-M solution of codeine.
c) What is the pH of the 0.050-M codeine solution?

Asolution is made by dissolving 25.5 grams of glucose (c6h12o6) in 398 grams of water. what is the freezing point depression of the solvent if the freezing point constant is -1.86 °c/m? show all of the work needed to solve this problem.

Why are the trends and exceptions to the trends in ionization energy observed?

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.