History

 

The earliest recorded history of HNO3 is attributed to the great early alchemist Jabir ibn Hayyan who first wrote about synthesising Nitric Acid.  He is considered by many to be the 'father of chemistry' and his research led to the discovery of Sulphuric Acid, then the first synthesis of Nitric Acid and Hydrochloric Acid. 

Later, in the Middle Ages when alchemists were searching for the Philosopher's stone, a mythical material which could turn any metal into gold, they discovered that Nitric Acid (Aqua Regia) was able to dissolve gold and platinum in water.

The ancient name for Nitric Acid is Aqua Regia which is a Latin expression literally translating as 'King's Water' or 'Royal Water'.  This is because Nitric Acid is one of the few substances capable of dissolving gold and platinum, which were known as the 'royal' or 'noble' metals.  Early alchemists called HNO3 Aqua Fortis which means 'Strong Water', Aqua Valens which means 'Powerful Water' or Spirit of Nitre. See History

 

Corrosive & Toxic

 

Pure HNO3 is a colourless liquid but older samples may take on a yellowish colour due to the accumulation of oxides of Nitrogen.   If a solution contains more than 86% Nitric Acid, it is called 'fuming' Nitric Acid, the word 'fuming' referring to the whitish fumes given off by the material.  Red Fuming HNO3 is produced depending on the amount of Nitrogen Dioxide present in the material. 

The earliest recorded history of Nitric Acid is attributed to the great early alchemist Jabir ibn Hayyan who first wrote about synthesising Nitric Acid.  He is considered by many to be the 'father of chemistry' and his research led to the discovery of Sulphuric Acid, then the first synthesis of HNO3 and Hydrochloric Acid.  Later, in the Middle Ages when alchemists were searching for the Philosopher's stone, a mythical material which could turn any metal into gold, they discovered that Nitric Acid (Aqua Regia) was able to dissolve gold and platinum in water.

Due to its 'Corrosive' and 'Toxic' properties, it is essential that all potential hazards of Nitric Acid are understood before handling or working with the material.  Personal Proective Clothing (PPE) must always be used and this will include protective clothing, rubber or plastic gloves, approved safety glasses or goggles and safety boots or shoes. 

Where there is a possibility of splashing, a full protective suits and face shield should be worn.  Nitric Acid should always be handled under fume extraction or at the least in a well-ventilated room.  If this is not possible, breathing apparatus should be worn. Read more on safety. 

Burns eyes & skin

 

HNO3 can cause serious burns to the eyes and skin, often causing long-term or permanent damage.  Inhalation of Nitric Acid will cause severe burns to the soft nasal tissue and the respiratory tract.  Ingestion of Nitric Acid will cause severe burns to the mouth, throat and digestive tract and again may cause life-threateneing damage. 

Large quantities or concentrations can cause fatal burns.  Full details of HNO3 safety can be found on the relevant pages of this website.

In the laboratory, Nitric Acid of 68% HNO by weight is most commonly used.  This is the same concentration as the constant boiling mixture of HNO3 with water.  This has the atmospheric pressure of 68.4% by weight and it boils at 121.9 degrees C.  Pure Nitric Acid is actually a colourless liquid with a boiling point of 86 degrees C which means that pure HNO3 should always be stored at below zero degrees C to avoid decomposition.

• Formula: HNO3
  
• Density: 1.51 g/cm³
  
• Molar mass: 63.01 g/mol
  
• IUPAC ID: Nitric acid
  
• Boiling point: 83 °C
  
• Melting point: -42 °C