Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which contains both of those minerals) and is the main component of pearls and the shells of marine organisms, snails, and eggs.
An ordinary breath for a 70-kg adult is about 500ml of air. We call this the tidal volume. Since oxygen is 21% by volume of air, then the volume of oxygen inhaled is about 105ml. The density of pure oxygen at sea level is 1.43kg per cubic metre.
A person breathes 7 or 8 liters of air per minute. Air is about 20% oxygen. But when you exhale, your breath is about 15% oxygen, so you consumed about 5%. Therefore, a person uses about 550 liters of pure oxygen each day. As for exhaled CO2, this site.