Question

Which gas we mix in colddrink to keep it fresh for a long time.

Answer 1

Explanation:

carbon dioxide gas

The fizz that bubbles up when you crack open a can of soda is carbon dioxide gas (CO2). Soft drink manufacturers add this tingling froth by forcing carbon dioxide and water into your soda at high pressures—up to 1,200 pounds per square inch.

Answer 2

it is liquid in gas which we mix the co2 into the cold drink to keep it fresh for a long time or to fight against acidity .

..... it helps in neutralization