Burps burn your nose after drinking soda?

the gas bubbles in your stomach have Hydrochloric acid acid fumes pH 2.0 in them . when you burp the acid fumes in the gas burns your nose. carbonic acid is no longer a gas its a liquid its week and you are belching carbon dioxide from the soda if it reacted with water it would react with the water in the drink and it does that , thats partly why all bubble drinks are acidic some have added phosphoric acid to drive the equilibrium back toward fizzy dissolved CO2 they usually have a little salt so any carbonic acid would react and form sodium bicarbonate a mild buffer. so a drink relies on phosphoric acid to maintain low acid pH to prevent spoilage due to heat resistant mold spores that remain viable in the sealed can but do not sporulate due to very low pH.

It's normal, and here's a guess about what's happening.

Carbonated drinks fizz because of carbon dioxide gas suspended in the water. The gas escapes when the liquid is not contained in a pressure vessel (can or bottle). Carbon dioxide and water together undergo a chemical reaction to form a very weak acid called carbonic acid. A burp after drinking something carbonated will be carbonic acid vapour. The internal membranes of the nasal cavity are very sensitive, and they react to acid. (Ever vomit and get puke up the back of your nose? It's a very unpleasant feeling.)