1360 Water chemistry and pH 1. The sweetener aspartame (=Equal) is made from two amino acids: aspartic acid and phenylalanine. (a) Draw its structure (skeletal) when pH is 1 . (b) Draw its structure (skeletal) when pH is 7. (c) Draw its structure (skeletal) when pH is 10 . 2. Carbonic acid (H2CO3) and bicarbonate (HCO3)act as buffers in the blood. (a) What is the origin of carbonic acid? (b) Write the equilibrium equation for dissociation of carbonic acid in water to give bicarbonate and hydronium ions. (c) Typical concentrations of carbonic acid and bicarbonate are 0.0024M and 0.024M, respectively. Calculate the pH of blood. (Ka of carbonic acid =4.3107) (d) Write a chemical equation that shows how the buffer neutralized added acid (H+)