Aspirin ( acetylsacylic acid, HAsp, Mr=180.2) is absorbed from stomach with thr form free acid. A patient takes some antiacid to adjust the pH of gastric juice to 2.95, and take 0.65g of aspirin. Assume aspirin dissolves immediately, and the pH of gastric juice is invariant. What is the mass of aspirin that the patient can absorb from stomach at once? pKa of acetysalicylic acid is 3.48.