Two friends go to an all-you-can eat restaurant but eat too much and get heartburn. Both return to their rooms and look for a remedy. One friend takes two tablets, each containing 750 mg CaCO₃, and the second friend takes 3 teaspoons of milk of magnesia, which contains 400 mg MgO per teaspoon. What will be the pH of each friend’s stomach after taking the medication, assuming a stomach acid volume of 100. mL and a concentration of HCl that is 0.10 mol · L^–1?