Mg ( OH )₂ is used as an antacid. If a person, suffering from acidity, produces 2.5 ~L of Gastric juice in a day, approximately how many antacid tablets, each containing 600 ~mg of Mg ( OH )₂ , will be required to completely neutralise the whole HCl produced in the stomach in one day? (Gastric juice contains 3.0 ~g of HCl per L). (Atomic masses: Mg =24 ~g / mol , O =16 ~g / mol & H =1 ~g / mol .)

Step-by-step solution

The total amount of HCl produced in the stomach per day is calculated as: Total HCl = 2.5 L 3.0 g/L = 7.5 g . The molar mass of HCl is 1 + 35.5 = 36.5 g/mol . The number of moles of HCl is n_ HCl = 7.5 36.5 0.2055 mol . The neutralization reaction is: Mg(OH) ₂ + 2 HCl MgCl ₂ + 2 H ₂ O . From the stoichiometry, 1 mole of Mg(OH) ₂ neutralizes 2 moles of HCl . Therefore, the required moles of Mg(OH) ₂ is n_ Mg(OH) ₂ = 0.2055 2 = 0.10275 mol . The molar mass of Mg(OH) ₂ is 24 + 2(16 + 1) = 24 + 34 = 58 g/mol . The mass