The pK, of citric acid is 3.09. What is the citric acid: monosodium citrate ratio in a 1.0 M citric acid solution with a pH of 2.09? A) 10:1 B) 1:1 C) 1:10 D) 10:11 E) 1:11 The pk, pk2, and PKR for the amino acid arginine are 1.8, 9.0, and 12.5, respectively. At pH 7.0 arginine would be charged predominantly as follows: A) a-carboxylate 0, a-amino 0, guanidino +1, net charge +1 B) a-carboxylate +1, a-amino 0, guanidino -1, net charge 0 C) a-carboxylate +1, a-amino-1, guanidino-1, net charge- D) a-carboxylate-1, a-amino +1, guanidino +1, net charge +1 E) a-carboxylate-1, a-amino 0, guanidino +1, net charge 0