a) Jim Bob analyses a buffer solution and finds it to contain in one liter: 0.220 moles of HA, and 0.430 moles of the conjugate base A-. If the Ka for the weak acid is 3.6 X 10-5. what is the pH of the buffer?
b) Ephedrine (EP) is a weak acid, protonated amine which you take if you find yourself over weight, or falling asleep in class. You can buy the hydrochloride salt (HEP+)Cl (like the hydrochoride salt of NH3: NH4Cl). The hydrochloride salt dissolves completely, and the weak acid dissociates slightly as shown in the reactions below.
HEPCl ----> EPH+ + Cl-
EPH+ <----> H+ + EP
pKa = 9.65
Calculate the pH of a solution the has 6.00 grams of HEPCl (molar mass: 201.7) dissolved in 120 mL after 9 mL of 0.68 KOH has been added
I need help with these two problems, please.