Q1: Freezing of 35% oleum during its shipment in winter is avoided by the addition of small amount of

ANS:D - nitric acid

Nitric acid, often referred to as aqua fortis or spirit of nitre, is a highly corrosive and strong mineral acid. Its chemical formula is HNO3. Nitric acid is a colorless to yellowish liquid with a pungent and acrid odor. Here are some key points about nitric acid:

1. Chemical Properties: Nitric acid is a strong acid, meaning it completely dissociates in water to form hydrogen ions (H+) and nitrate ions (NO3-). It is a powerful oxidizing agent and can react vigorously with many substances, particularly reducing agents.
2. Uses: Nitric acid has numerous industrial applications, including:
   • Production of fertilizers: It is used in the production of ammonium nitrate, a common fertilizer.
   • Production of explosives: Nitric acid is a key component in the manufacture of explosives such as TNT (trinitrotoluene).
   • Metal etching and finishing: It is used to etch metals and alloys and in the preparation of metal surfaces for plating.
   • Organic synthesis: Nitric acid is used in the synthesis of various organic compounds.
3. Safety Precautions: Due to its corrosive and oxidizing nature, nitric acid must be handled with extreme caution. It can cause severe burns upon contact with skin and mucous membranes. Inhalation of its vapors can irritate the respiratory tract and lungs. Proper personal protective equipment, such as gloves, goggles, and a respirator, should be worn when handling nitric acid.
4. Environmental Impact: Nitric acid is a hazardous substance that can cause environmental pollution if not handled and disposed of properly. Spills of nitric acid can contaminate soil, groundwater, and surface water, leading to environmental damage.