A Rolaids tablet contains calcium for neutralizing stomach acid. if a Rolaids tablet neutralizes 24.65ml of 0.547m hydrochloric acid, how many milligrams of calcium carbonate are in a Rolaids tablet?

There are 674 mg of calcium carbonate in a Rolaids tablet

Further explanation

Reaction

CaCO₃ + 2HCl ⇒ CaCl₂ + CO₂ +H₂O

V HCl = 24.65 ml

M HCl = 0.547

mol HCl :

ratio mol CaCO₃ : HCl = 1 : 2, so mol CaCO₃ :

mass of CaCO₃ (MW=100~g/mol) :

We calculate for the number of moles of water given its mass by dividing the given mass by the molar mass. 
                               n water = (36.04 g) / (18 g/mol) 
                                n water = 2 mols
From the given balanced equation, every 6 moles of water produced will require 7 moles of oxygen.
                                n oxygen = (2 mols H2O) x (7 moles O2 / 6 moles H2O)
                                n oxygen  = 2.33 mols O2