<prompt> Yellow discoloration of the skin and the mucosa is seen in which poisoning?Nitrous oxideNitric acidSulphuric acidPhosphoric acid  <response>: Ans. is b i.e., Nitric acid o Nitric acid causes yellow discoloration of the tissues including the crowns of the teeth yellow stains on the clothing,o Inhalation of fumes causes lacrimation, photophobia, irritation of air-passages lungs producing sneezing, coughing, dyspnea asphyxia,o The color of urine is brown.PoisonPattern of MucosaArsenicRed velvety mucosa of the stomachH2SO4Brown of Black with erosion, perforation CarbolizationCarbolic AcidGreen w hite of Brow n - white or Grey leathery- and thickened mucosaHNO3YellowHC1PinkAmmoniaPerforatedHCNPinkKCNBrick red to brownKOH, NaOHDeeply congested. BlackPhosphorusYellow or grey white 