Introduction to Nitric Acid
Nitric acid might sound like a chemical you’d only find in science labs, but it plays a huge role in everyday life across Australia. From helping Aussie farmers grow crops with fertilisers to its use in mining operations, nitric acid is a key player in several industries. Let’s dive into what makes it so important, its uses, and the precautions needed when handling it.
What is Nitric Acid?
Nitric acid is a highly corrosive, colourless to yellow liquid with the chemical formula HNO₃. It’s one of the most significant inorganic acids in the world.
Historical Discovery
The acid was first discovered by European alchemists in the 13th century. Back then, it was referred to as “aqua fortis” or “strong water” because of its ability to dissolve metals.
Physical Properties of Nitric Acid
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Appearance: Clear, colourless liquid (sometimes yellow if it decomposes).
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Odour: Sharp, acrid smell.
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Boiling point: Around 83°C.
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Melting point: -42°C.
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Solubility: Completely soluble in water, making it easy to prepare in diluted forms.
Chemical Properties of Nitric Acid
Nitric acid is both a strong acid and a powerful oxidiser.
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With metals, it produces metal nitrates and often releases nitrogen oxides.
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With bases, it neutralises to form salts and water.
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It can even oxidise non-metals such as sulphur and phosphorus.
Production of Nitric Acid
Laboratory Preparation
In laboratories, nitric acid is made by reacting potassium nitrate with concentrated sulphuric acid.
Industrial Production – The Ostwald Process
The Ostwald process is the main industrial method used worldwide, including in Australia’s chemical plants. It involves:
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Oxidising ammonia (NH₃) to nitric oxide (NO).
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Converting NO into nitrogen dioxide (NO₂).
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Absorbing NO₂ in water to form HNO₃.
This large-scale method is vital for Australia’s agricultural and mining sectors.
Grades of Nitric Acid
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Concentrated nitric acid: Around 68–70% pure, mainly used in industries.
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Dilute nitric acid: Below 30%, common in labs and smaller applications.
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Fuming nitric acid: Almost 100% pure, extremely dangerous, emits visible red or white fumes.
Uses of Nitric Acid in Everyday Life
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Found in school science labs for experiments.
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Used in metal cleaning and jewellery polishing.
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Plays a part in engraving and etching designs.
Industrial Applications of Nitric Acid in Australia
Fertiliser Production
Nitric acid is crucial in producing ammonium nitrate, which supports Australia’s vast agricultural sector. From wheat in Western Australia to sugarcane in Queensland, farmers rely heavily on fertilisers derived from nitric acid.
Explosives Manufacturing
Nitric acid is essential in producing explosives like TNT and nitroglycerin, which are used widely in Australia’s mining industry—a backbone of the national economy.
Dyes and Pigments
It’s used in manufacturing dyes for textiles and pigments for paints, serving both industrial and artistic applications.
Pharmaceuticals
Certain Australian pharmaceutical products require nitric acid in their production.
Nitric Acid in Agriculture
Australia’s farmers benefit from nitric acid indirectly through fertilisers like ammonium nitrate and urea nitrate. These fertilisers boost crop yields and help meet the demands of both domestic markets and exports.
Hazards of Nitric Acid
Despite its usefulness, nitric acid is dangerous.
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Corrosive: Causes burns and permanent tissue damage.
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Inhalation risks: Fumes containing nitrogen dioxide can cause serious lung injury.
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Environmental hazards: Contributes to acid rain and water contamination.
First Aid Measures for Nitric Acid Exposure
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Skin contact: Wash the area with plenty of water immediately.
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Eye exposure: Flush eyes with clean water for at least 15 minutes, then seek medical help.
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Inhalation: Move to fresh air straight away and seek urgent care.
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Ingestion: Do not induce vomiting—call emergency services immediately.
Safe Handling and Storage of Nitric Acid
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Always wear gloves, safety goggles, and protective clothing.
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Store in ventilated, cool storage areas away from organic or flammable materials.
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Transport nitric acid in containers specifically designed to handle corrosives.
Environmental Impact of Nitric Acid in Australia
Nitric acid plays a part in forming acid rain, which can harm Australia’s ecosystems—from farmland soils to aquatic environments like the Murray-Darling Basin. Spills and leaks can contaminate groundwater, posing risks to both humans and wildlife.
Nitric Acid and Human Health
Short-term exposure causes burns, breathing problems, and eye injuries, while long-term exposure may lead to chronic respiratory diseases. Strict workplace safety laws in Australia ensure workers handling nitric acid are well protected.
Future Trends and Innovations
The future of nitric acid production in Australia is moving towards sustainability. Researchers are developing green chemistry methods and renewable-energy-based processes to reduce environmental impacts while meeting industrial demand.
Conclusion
Nitric acid is both dangerous and indispensable. In Australia, it fuels agriculture, powers the mining industry, and supports scientific research. But just like fire, it needs to be handled carefully. With strict safety standards and ongoing innovations, nitric acid will continue to play a vital role in the nation’s growth.
FAQs
1. What’s the most common use of nitric acid in Australia?
Fertiliser production—especially ammonium nitrate for farming.
2. Is nitric acid used in Australia’s mining industry?
Yes, it’s widely used in explosives manufacturing for mining and quarrying.
3. Why is nitric acid sometimes yellow?
It turns yellow when nitrogen oxides dissolve in it.
4. Can nitric acid harm the environment?
Yes, it can contribute to acid rain and pollute waterways if not managed properly.
5. Does Australia produce nitric acid locally?
Yes, local chemical plants produce it, mainly for the agriculture and mining industries.