You are asked to prepare 500. mL 0.200 M acetate buffer at pH 4.90 using only pure acetic acid ( MW=60.05 g/mol, pKa=4.76), 3.00 M NaOH, and water. How many grams of acetic acid will be needed to prepare the 500. mL buffer? Note that the given concentration of acetate refers to the concentration of all acetate species in solution.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.