I'm not quite sure how to go about solving this one:
Gastric Juice is essentially a solution of HCl and the enzyme pepsin. It has a normal pH in the range of 0.3-1.2, with the lower figure leading to hyperacidity. Relief from hyperacidity is provided by antacids, such as Al(OH)3. What mass of Al(OH)3 must be used in an antacid tablet designed to increase the pH of 500 mL of gastric juice from 0.3 to 1.2?
Al(OH)3 = 78.0 g/mol
the answer is 5.7 grams, not sure how to get there though.