Project Summary: Calculate the pH of the Stomach if the HCL acid is pumped into it from the stomach lining at a concentration of 7. 2 * 10-2. A buffer is made of an acid and the sodium or potassium salt its conjugate base. What is the conjugate base of Na2HPO4 acid? What is the molarity (in OH-, hydroxide) of a base( KOH) whose pH is 11.1 ?