In industrial soft drink manufacturing, which gas is used for the preparation of soda water?

Introduction / Context:
Soda water, also called carbonated water, is a very common beverage found in soft drinks and fizzy mineral waters. In chemistry and general science, it is important to know which gas is dissolved under pressure to give soda water its characteristic bubbles and tangy taste. This question checks basic awareness of gases used in the food and beverage industry and reinforces the concept of gas solubility in liquids.

Given Data / Assumptions:

• Soda water is a form of water with a gas dissolved in it under pressure.
• The gas must be safe for human consumption in moderate amounts.
• Options include common gases such as carbon dioxide, oxygen, hydrogen, ammonia, and nitrogen.
• We consider typical commercial soda water used in soft drinks and not special laboratory preparations.

Concept / Approach:
Carbon dioxide is a colourless, odourless gas that dissolves in water to form a weak acid called carbonic acid. When bottled under pressure, carbon dioxide remains dissolved. On opening the bottle, the pressure drops and bubbles of carbon dioxide escape, producing effervescence. Other gases like oxygen and nitrogen are present in air but are not usually used to carbonate beverages. Ammonia and hydrogen would be unsafe or unsuitable in this context. Therefore, the correct gas used in preparing soda water is carbon dioxide.

Step-by-Step Solution:
Step 1: Recall that soda water is fizzy and forms bubbles when the bottle is opened, so a gas is escaping from the liquid. Step 2: In soft drink factories, water is chilled and exposed to carbon dioxide gas under high pressure so that the gas dissolves in it. Step 3: Carbon dioxide reacts slightly with water to form carbonic acid, giving soda water a mildly acidic taste. Step 4: When the container is opened, the pressure on the liquid decreases, and dissolved carbon dioxide comes out as bubbles. Step 5: Oxygen, hydrogen, ammonia, and nitrogen are not routinely used to carbonate drinks because they do not give the same safe and pleasant effect. Step 6: Thus, the gas used in the preparation of soda water is carbon dioxide.

Verification / Alternative check:
Labels on soft drink bottles often state that the drink is carbonated with carbon dioxide and sometimes list carbon dioxide as an ingredient. In chemistry experiments, when carbon dioxide is passed through water, similar effervescence is observed. Furthermore, the term carbonation itself commonly refers to dissolving carbon dioxide in a liquid. These practical observations and industry practices confirm that carbon dioxide is the gas responsible for soda water preparation.

Why Other Options Are Wrong:
Oxygen: Dissolved oxygen is important for aquatic life but does not produce the strong fizz and is not used as a carbonating gas in soft drinks.
Hydrogen: It is highly flammable and unsafe for use in beverages; it is not used to make soda water.
Ammonia: A pungent and irritating gas used in some cleaning products, not suitable to dissolve in drinking water.
Nitrogen: Sometimes used in special beverages to change texture, but classical soda water is made with carbon dioxide, not nitrogen as the main gas.

Common Pitfalls:
Students sometimes confuse carbon dioxide with oxygen because both are familiar atmospheric gases. Another mistake is to think that any gas can be used, ignoring safety and taste. Some may also think that the fizz comes simply from air. Remember that carbonation specifically refers to carbon dioxide, and that this gas provides the characteristic tang and bubbles of soda water while remaining safe in controlled amounts.

Final Answer:
Carbon dioxide is the gas used for the preparation of soda water in soft drink manufacturing.