___ g of oxygen is required to completely react with 12 g of carbon to form carbon dioxide.
Calcium carbonate reacts with aqueuaq HCl to give calcium chloride and carbon dioxide according to the reaction .
CaCl2 (s) + 2HCl (aq.) = CaCl2 (aq) + CO2 (g) + H2O (l)
What mass of calcium carbonate is required to react completely with 25ml of 0.75M HCl?