Magnesium hydroxide neutralises stomach acid by Mg(OH)2 + 2HCl -> MgCl2 + 2H2O. Using atomic masses H = 1, O = 16 and Mg = 24, how many millimoles of HCl can 1.60 g of Mg(OH)2 neutralise?

JEE Main levelSingle correct optionDifficulty 2 of 3el071

Magnesium hydroxide neutralises stomach acid by $Mg (OH) X_{2} + 2 HCl MgCl X_{2} + 2 H X_{2} O$ . Using atomic masses H = 1, O = 16 and Mg = 24, how many millimoles of $HCl$ can $1.60 g$ of $Mg (OH) X_{2}$ neutralise?

Molar mass of

Mg (OH) X_{2}

= 24 + 2(16 + 1) = 58 g/mol, so moles = 1.60/58 = 0.02759 mol. Each mole neutralises 2 mol of HCl, giving 0.05517 mol = 55.17 mmol.