Nitric acid.

 Reactions with metals: Nitric acid dissolves most metals including iron, copper, and silver, with generally the liberation of lower oxides of nitrogen rather than hydrogen. It can also dissolve the noble metals with the addition of hydrochloric 2H2O  Reactions with nonmetals: Reaction with non-metallic elements, with the exception of silicon and halogen, usually oxidizes them to their highest oxidation states as acids with the formation of nitrogen dioxide for concentrated acid and nitrogen oxide for by The gases by combustion of coal in the Then the vapour of nitric acid are cooled and condensed in water cooled silica pipes. The cooled acid is collected in stoneware receiver. The un-condensed vapours are scrubbed with water in absorption tower which is packed with stone ware balls and cooled by cold water. The dilute acid is re-circulated till it becomes concentrated. The residual sodium bisulfate is removed by outlet provided at the bottom of