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.
Some medications especially pain medications can lower your respiration rate also . Normal breathing rates fall between 12-20 per minute. Either above or below this range will result in inadequate profusion.  If a person had 70-90 breathes in one minute, they wouldn't be human anymore. The average adult breathes in and out every 4-5 seconds or so. If you are an adult and your respiration are between 12 and 25, then you need not worry. Outside of that (when your body is at rest), then you should be worried.