Which first-line of defense uses acids to kill pathogens?

Stomach Acid

Explanation:

Stomach acid destroys bacteria that have been eaten and parasites. From the bladder region, the urine flow flushes out contaminants. In combating bacteria, skin, tears and mucus are part of the first line of defense. They continue to shield us from diseases attacking us.

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .