Extremely poisonous and corrosive acid among all acids, NITRIC ACID!!

A member of the class of inorganic acids, nitric acid is a conjugate acid of nitrate. As indicated by the symbol HNO3, the nitrogen atom is joined to two oxygen atoms and a hydroxyl group. It is a good conductor of electricity, has a molecular weight of 63.013 g/mol, and is very soluble in water. Following distillation, pure nitric acid starts to boil at 78.2°C and solidifies after being thoroughly cooled.

When nitric acid is fresh, it is colourless; but, as it ages, the buildup of nitrogen oxides causes it to turn yellow. Nitric acid is a strong oxidizing agent. It easily ionises in solution and becomes a good electrical conductor. It forms nitrate salts when it interacts with metals, oxides, and hydroxides.

Pure anhydrous nitric acid (100%) solidifies at -42° C and takes the shape of white crystals. It is a colourless, mobile liquid with a density of 1.512 g/cm2. At 83⁰ C, it starts to boil. In order to prevent decomposition, anhydrous nitric acid should be stored below 0°C.

Commercial grade, which is of medium quality, often contains water and nitric acid solutions that range in concentration from 52% to 68% nitric acid. Laboratories require a higher quality, and their concentrations of nitric acid are often between 70% and 99%. A solution is referred to as fuming nitric acid when it contains more than 86% nitric acid. Fumigating nitric acid can also be classified as red fuming nitric acid at concentrations over 86% or white fuming nitric acid at concentrations above 95%, depending on the amount of nitrogen dioxide present.

Caution: Nitric acid may damage a metal pump if you use it. To handle considerably larger nitric acid concentrations, use a plastic pump, which is what you should use.

Nitric acid is exceedingly poisonous and corrosive. Nitric acid fumes have a sour, suffocating smell and are extremely hazardous. To tissues, metals, and even some polymers, the liquid form is corrosive. Direct contact can therefore cause serious burns. Use caution and use the appropriate PPE when handling nitric acid.

The Ostwald process, which was name after the name of German chemist Wilhelm Ostwald, is primarily used produce Nitric Acid by oxidise ammonia. Anhydrous ammonia is converted to nitric oxide during this process, which takes place at a high temperature of around 500K and a pressure of 9 bar in the presence of a platinum or rhodium gauge catalyst. Sulfuric acid is used to process sodium nitrate to yield minute quantities. One of the ingredient in acid rain is nitric acid.

Step 1: Formation of Nitric Oxide

4NH₃ + 5O₂ ↔ 4NO + 6H₂O | H -24.8 Kcal/mol (Catalyst: platinum gauze or copper and nickel)

Step 2: Formation of Nitrogen Dioxide

2NO + O₂ ↔2 NO₂

Step 3: Formation of Nitric Acid

3NO₂ + H₂O -> 2HNO₃ + NO

Nitrogen dioxide (NO2) reacts with water to create nitric acid. The nitric oxide that results from the process is often re-oxidized by the oxygen in the air to yield more nitrogen dioxide. It is possible to create practically pure nitric acid by mixing sulfuric acid with a nitrate salt and heating the combination in an oil bath. The vapours of nitric acid that escape from the solution are condensed using a condenser.

Strong nitric acid is created industrially by dissolving extra nitrogen dioxide in 68% nitric acid in an absorption tower. When nitrogen oxides are dissolved, they either get taken away to create white fuming nitric acid or they stay in solution to create red fuming nitric acid. The production of anhydrous acid from concentrated nitric acid feedstock has recently been made possible using electrochemical methods.

Nitric acid is mostly used to make fertilisers like ammonium nitrate and explosives like nitroglycerin and trinitrotoluene (TNT). Additionally, it is employed in metallurgy, ore flotation, steel etching, photoengraving, and the recycling of spent nuclear fuel in the production of chemicals, such as dyes. Another frequently employed strong oxidising agent is nitric acid.

Many different processes and businesses use nitric acid extensively. The key applications in the various industries are listed below,

1. Fertilizers

Making fertiliser is nitric acid's main industrial application. Nitric acid, as ammonium nitrate, is a fantastic fertiliser when coupled with ammonia. Calcium nitrate is another synthetic fertiliser. All around the nation, farms employ these fertilisers.

2. Explosives

Numerous forms of explosives, including nitroglycerin and trinitroglycerin, are produced using nitric acid (TNT). These are utilised for national defence and are of military grade.

3. Dye Intermediate

Numerous industrial dyes can be processed using nitric acid when it is transformed into calcium ammonium nitrate.

4. Laboratory Use

A crucial component for laboratory work is nitric acid. It functions as a pH buffer, a cleaning agent, and a preservative for water samples that need to be cleaned up for metal analysis.

5. Drug Detection

In a colorimetric test, nitric acid can be used to distinguish between heroin and morphine. Additionally crucial is the ability to identify LSD in spot tests.

6. Adhesive

A frequent ingredient in the adhesive used in food packaging and paperboard is nitric acid.

7. Medicinal

Nitric acid can be used to treat boils and warts since it is caustic in its pure form. It can be used to cure indigestion if it is diluted.

8. Purifying Metals    

Platinum, gold, and silver are examples of noble metals that can be cleaned and purified using nitric acid. When coupled with hydrochloric acid, it creates aqua regia, a substance that may even dissolve platinum and gold. Jewelers typically purify noble metals.

9. Furniture Coating

The main ingredient in furniture varnish is nitric acid. It is therefore frequently utilised as a lacquer when coloured pigment is added to it. Even pine and maple wood can appear artificially aged thanks to it.

10. Engraving

Nitric acid and alcohol can be used to etch patterns into a variety of metals, including copper, bronze, and brass. Typically, these are utilised in house decor.

Since nitric is used in so many industries, identifying the top 10 uses for it would only scrape the surface. Additionally, it serves as a component of liquid rocket fuel, a crucial ingredient in the production of polymers, and a cleaning agent in facilities that handle food.