Sodium bicarbonate, also known as baking soda, is a common item used in baking and for other household purposes. Laboratories also use sodium bicarbonate to neutralise acidic chemicals and as a buffer for pH levels. Making sodium bicarbonate involves using dangerous materials. Do not attempt it without proper equipment or training.
Mix 40g of sodium chloride in 100ml of water. If you can't tell if the solution is saturated, stop here and do not proceed. If you're sure that the solution is saturated, decant it into the gas bubbler.
Bubble ammonia gas in the fume hood through the saturated sodium chloride solution. It should only take a couple of minutes to saturate the solution with ammonia gas. Be sure to catch the excess ammonia in a gas trap.
With the chemicals still in the fume hood, bubble carbon dioxide through the solution. The sodium bicarbonate will precipitate out.
Filter the sodium bicarbonate carefully from the solution using gravity filtration.
Allow to air dry. Properly dispose of the leftover solution which contains leftover ammonium chloride, sodium chloride and sodium carbonate.
This process is know as the Solvay process.
The danger of ammonia gas cannot be stressed enough. Only do work with this chemical inside of a properly working fume hood. Always wear proper laboratory safety equipment. Never work alone. This is an extremely dangerous lab. It is an unrealistic way to prepare sodium bicarbonate for personal use, since you can buy baking soda, which is sodium bicarbonate. No reputable business will sell ammonia gas to an individual.