Nitric acid
IUPAC name	Nitric acid
Other names	Aqua fortis; Spirit of nitre; Salpetre acid; Hydrogen Nitrate
Identifiers
CAS number	[7697-37-2]
RTECS number	QU5775000
SMILES	O[N+](=O)[O-]
Properties
Molecular formula	HNO3
Molar mass	63. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 012 g/mol
Appearance	Clear, colorless liquid
Density	1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 51 g/cm³, colorless liquid
Melting point	-42 °C, 231 K, -44 °F
Boiling point	83 °C, 356 K, 181 °F (bp of pure acid. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 68% solution boils at 120. 5°C)
Solubility in water	miscible
Viscosity	? cP at ? °C
Dipole moment	2. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Viscosity is a measure of the resistance of a Fluid which is being deformed by either Shear stress or Extensional stress. The poise (symbol P pwɑːz is the unit of dynamic Viscosity in the Centimetre gram second system of units. In physics there are two kinds of dipoles ( Hellènic: di(s- = two- and pòla = pivot hinge An electric dipole is a 17 ± 0. 02 D
Hazards
EU classification	Oxidant (O) Corrosive (C)
R-phrases	R8, R35
S-phrases	(S1/2), S23, S26, S36, S45
Flash point	not applicable
Related compounds
Related compounds	Nitrous acid Dinitrogen pentoxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Nitric acid (HNO₃), also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid that can cause severe burns. The debye (symbol D) is a non- SI, CGS unit of electrical dipole moment. Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air Nitrous acid (molecular formula H[[Nitrogen N]] O 2 is a weak and monobasic Acid known only in Solution and in the form of Nitrite Dinitrogen pentoxide is the Chemical compound with the formula N2O5 In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Toxicity is the degree to which a substance is able to damage an exposed organism A Strong acid is an Acid that Ionizes completely in an Aqueous solution (not in the case of Sulfuric acid as it is diprotic The synthesis of nitric acid was first recorded circa 800 AD by the alchemist Jabir ibn Hayyan. Events By Place Europe September 15 - Oldest known mention of Monkey. Alchemy a part of the Occult Tradition is both a philosophy and a practice with an ultimately unknown aim involving the improvement of the alchemist as well as the making of For the 12th century astronomer see Jabir ibn Aflah. For the anonymous 14th century Spanish alchemist see Pseudo-Geber. ^[1]

Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric If the solution contains more than 86% nitric acid, it is referred to as fuming nitric acid. Fuming nitric acid is characterized as white fuming nitric acid and red fuming nitric acid, depending on the amount of nitrogen dioxide present. White fuming nitric acid ( WFNA) is a storable liquid Oxidizer used with kerosene and hydrazine Rocket fuel. Red fuming nitric acid ( RFNA) is a storable Oxidizer used as a Rocket propellant. Nitrogen tetroxide ( dinitrogen tetroxide or nitrogen peroxide) is the Chemical compound N2O4

Properties

Pure anhydrous nitric acid (100%) is a colorless liquid with a density of 1522 kg/m³ which solidifies at -42 °C to form white crystals and boils at 83 °C. When boiling in light, even at room temperature, there is a partial decomposition with the formation of nitrogen dioxide following the reaction:

4HNO₃ → 2H₂O + 4NO₂ + O₂ (72°C)

which means that anhydrous nitric acid should be stored below 0 °C to avoid decomposition. Decomposition (or spoilage) refers to the break down of tissue of a formerly living Organism into simpler forms of matter The nitrogen dioxide (NO₂) remains dissolved in the nitric acid coloring it yellow, or red at higher temperatures. Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2 While the pure acid tends to give off white fumes when exposed to air, acid with dissolved nitrogen dioxide gives off reddish-brown vapours, leading to the common name "red fuming acid" or "fuming nitric acid".

Nitric acid is miscible with water in all proportions and distillation gives an azeotrope with a concentration of 68% HNO₃ and a boiling temperature of 120. Miscibility is a term commonly used in Chemistry that refers to the property of Liquids to mix in all proportions forming a Homogeneous Solution Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture An azeotrope (pronounced 5 °C at 1 atm. Two solid hydrates are known; the monohydrate (HNO₃·H₂O) and the trihydrate (HNO₃·3H₂O).

Nitrogen oxides (NO_x) are soluble in nitric acid and this property influences more or less, all the physical characteristics depending on the concentration of the oxides. The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric These mainly include the vapor pressure above the liquid and the boiling temperature, as well as the color mentioned above.

Nitric acid is subject to thermal or light decomposition with increasing concentration and this may give rise to some non-negligible variations in the vapour pressure above the liquid because the nitrogen oxides produced dissolve partly or completely in the acid. A thermal column (or thermal) is a column of rising Air in the lower altitudes of the Earth's atmosphere. In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance

Acidic properties

Being a typical acid, nitric acid reacts with alkalis, basic oxides, and carbonates to form salts, such as ammonium nitrate. In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal In Chemistry, a basic oxide is an Oxide that either reacts with Water to have a proton transferred to it reacts with an In Chemistry, a carbonate is a salt or Ester of Carbonic acid. A salt, in Chemistry, is defined as the product formed from the neutralisation reaction of Acids and bases. The Chemical compound ammonium nitrate, the Nitrate of Ammonia with the chemical formula N[[Hydrogen H]]4 N[[Oxygen O]]3 Due to its oxidizing nature, nitric acid generally does not donate its proton (that is, it does not liberate hydrogen) on reaction with metals and the resulting salts are usually in the higher oxidized states. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across For this reason, heavy corrosion can be expected and should be guarded against by the appropriate use of corrosion resistant metals or alloys. Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has

Nitric acid has an acid dissociation constant (pK_a) of −1. 4: in aqueous solution, it almost completely (93% at 0. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances 1 mol/L) ionizes into the nitrate ion NO₃⁻ and a hydrated proton, known as a hydronium ion, H₃O⁺. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Hydrate is a term used in Inorganic chemistry and Organic chemistry to indicate that a substance contains Water. The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive In Chemistry, hydronium is the obsolete name for the Cation H 3 O + derived from Protonation of Water

HNO₃ + H₂O → H₃O⁺ + NO₃^-

Oxidizing properties

Reactions with metals

Being a powerful oxidizing agent, nitric acid reacts violently with many organic materials and the reactions may be explosive. Depending on the acid concentration, temperature and the reducing agent involved, the end products can be variable. Reaction then takes place with all metals except the precious metal series and certain alloys. Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. As a general rule of course, oxidizing reactions occur primarily with the concentrated acid, favouring the formation of nitrogen dioxide (NO₂). Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2

Cu + 4HNO₃ → Cu(NO₃)₂ + 2NO₂ + 2H₂O

The acidic properties tend to dominate with dilute acid, coupled with the preferential formation of nitrogen oxide (NO). The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric

3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

Since nitric acid is an oxidizing agent, hydrogen (H₂) is rarely formed. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Only magnesium (Mg), Manganese (Mn) and calcium (Ca) react with cold, dilute nitric acid to give hydrogen:

Mg_(s) + 2HNO_{3 (aq)} → Mg(NO₃)_{2 (aq)} + H_{2 (g)}

Passivation

Although chromium (Cr), iron (Fe) and aluminium (Al) readily dissolve in dilute nitric acid, the concentrated acid forms a metal oxide layer that protects the metal from further oxidation, which is called passivation. Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 WikipediaNaming Passivation is the process of making a material "passive" in relation to another material prior to using the materials together

Reactions with non-metals

Reaction with non-metallic elements, with the exception of silicon and halogens, usually oxidizes them to their highest oxidation states as acids with the formation of nitrogen dioxide for concentrated acid and nitrogen oxide for dilute acid. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions The oxidation number of a central atom in a coordination compound is the charge that it would have if all the Ligands were removed along with the Electron pairs Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2 The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric

C + 4HNO₃ → CO₂ + 4NO₂ + 2H₂O

or

3C + 4HNO₃ → 3CO₂ + 4NO + 2H₂O

Grades

White fuming nitric acid, also called 100% nitric acid or WFNA, is very close to the anhydrous nitric acid product. One specification for white fuming nitric acid is that it has a maximum of 2% water and a maximum of 0. 5% dissolved NO₂.

Red fuming nitric acid, or RFNA, contains substantial quantities of dissolved nitrogen dioxide (NO₂) leaving the solution with a reddish-brown color. One formulation of RFNA specifies a minimum of 17% NO₂, another specifies 13% NO₂.

An inhibited fuming nitric acid (either IWFNA, or IRFNA) can be made by the addition of 0. 6 to 0. 7% hydrogen fluoride, HF. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. This fluoride is added for corrosion resistance in metal tanks (the fluoride creates a metal fluoride layer that protects the metal).

Industrial production

Nitric acid is made by mixing nitrogen dioxide (NO₂) with water in the presence of oxygen or air to oxidize the nitrous acid also produced by the reaction. Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2 Water is a common Chemical substance that is essential for the survival of all known forms of Life. Nitrous acid (molecular formula H[[Nitrogen N]] O 2 is a weak and monobasic Acid known only in Solution and in the form of Nitrite

Dilute nitric acid may be concentrated by distillation up to 68% acid, which is an azeotropic mixture with 32% water. An azeotrope (pronounced Further concentration involves distillation with sulphuric acid which acts as a dehydrating agent. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. In the laboratory, such distillations must be done with all-glass apparatus at reduced pressure, to prevent decomposition of the acid.

Commercial grade nitric acid solutions are usually between 52% and 68% nitric acid. Commercial production of nitric acid is via the Ostwald process, named after Wilhelm Ostwald. The Ostwald process is a chemical process for producing Nitric acid, which was developed by Wilhelm Ostwald (patented 1902 Friedrich Wilhelm Ostwald ( Latvian: Vilhelms Ostvalds; September 2, 1853 &ndash April 4, 1932) was a Baltic

The acid can also be synthesized by oxidizing ammonia, but the product is diluted by the water also formed as part of the reaction. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance However, this method is important in producing ammonium nitrate from ammonia derived from the Haber process, because the final product can be produced from nitrogen, hydrogen, and oxygen as the sole feedstocks. The Chemical compound ammonium nitrate, the Nitrate of Ammonia with the chemical formula N[[Hydrogen H]]4 N[[Oxygen O]]3 The Haber process, also called the Haber–Bosch process, is the Nitrogen fixation reaction of Nitrogen and Hydrogen, over an iron substrate

Laboratory synthesis

In laboratory, nitric acid can be made from copper(II) nitrate or by reacting approximately equal masses of potassium nitrate (KNO₃) with 96% sulfuric acid (H₂SO₄), and distilling this mixture at nitric acid's boiling point of 83 °C until only a white crystalline mass, potassium hydrogen sulfate (KHSO₄), remains in the reaction vessel. Copper(II nitrate is the Chemical compound with the formula Cu ( NO3)2 Potassium nitrate is a Chemical compound with the Chemical formula K[[Nitrogen N]] O 3 Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture Potassium bisulfate is the Potassium salt of Bisulfate anion with the molecular formula KHSO4 The obtained red fuming nitric acid may be converted to the white nitric acid.

H₂SO₄ + KNO₃ → KHSO₄ + HNO₃

The dissolved NO_x are readily removed using reduced pressure at room temperature (10-30 min at 200 mmHg or 27 kPa) to give white fuming nitric acid. The term nitrogen oxide typically refers to any Binary compound of Oxygen and Nitrogen, or to a mixture of such compounds Nitric The torr (symbol Torr) is a non- SI unit of Pressure defined as 1/760 of an atmosphere. This procedure can also be performed under reduced pressure and temperature in one step in order to produce less nitrogen dioxide gas. Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2

Uses

Nitric acid in a laboratory.

IWFNA may be used as the oxidizer in liquid fuel rockets. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Rocket propellant is mass that is stored usually in some form of Propellant tank prior to being used as the propulsive mass that is ejected from a rocket engine in the form IRFNA was one of 3 liquid fuel components for the BOMARC missile ^[2]

A solution of nitric acid and alcohol, Nital, is used for etching of metals to reveal the microstructure. The CIM-10 Bomarc (originally IM-99) was the product of the Bomarc Missile Program. Nital is a solution of Alcohol and Nitric acid commonly used for routine etching of Metals.

Commercially available aqueous blends of 5-30% nitric acid and 15-40% phosphoric acid are commonly used for cleaning food and dairy equipment primarily to remove precipitated calcium and magnesium compounds (either deposited from the process stream or resulting from the use of hard water during production and cleaning).

Digestion

In elemental analysis by ICP-MS, ICP-AES, GFAA, and Flame AA, dilute nitric acid (0. Elemental analysis is a process where a sample of some material (e ICP-MS ( Inductively coupled plasma mass spectrometry) is a type of Mass spectrometry that is highly sensitive and capable of the determination of a range of Metals Inductively coupled plasma atomic emission spectroscopy (ICP-AES also referred to as inductively coupled plasma optical emission spectrometry (ICP-OES is an analytical technique used 5 to 5. 0 %) is used as a matrix compound for determining metal traces in solutions. ^[3] Fact|date=January 2008}} Ultrapure acid is required for such determination, because small amounts of metal ions could affect the result of the analysis.

Woodworking

In a low concentration (approximately 10%), nitric acid is often used to artificially age pine and maple. This article is about the tree For other uses of the term "pine" see Pine (disambiguation. Acer ( maple) is a Genus of Trees or Shrubs They are variously classified in a family of their own the Aceraceae, or The color produced is a grey-gold very much like very old wax or oil finished wood (wood finishing). Wood finishing refers to the process of embellishing and/or protecting the surface ^[4]

Other uses

Alone, it is useful in metallurgy and refining as it reacts with most metals, and in organic syntheses. Metallurgy is a domain of Materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their Refining (also called affining) is the process of Purification of a substance. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across In Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products When mixed with hydrochloric acid, nitric acid forms aqua regia, one of the few reagents capable of dissolving gold and platinum. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78

Safety

Nitric acid is a powerful oxidizing agent, and the reactions of nitric acid with compounds such as cyanides, carbides, and metallic powders can be explosive. An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound A cyanide is any Chemical compound that contains the cyano group (C≡N which consists of a Carbon Atom triple-bonded to a For the Software development tool targeting the Symbian OS, see Carbide An explosive material is a material that either is chemically or otherwise Energetically unstable or produces a sudden expansion of the material usually accompanied Reactions of nitric acid with many organic compounds, such as turpentine, are violent and hypergolic (i. Turpentine (also called spirit of turpentine oil of turpentine wood turpentine gum turpentine is a fluid obtained by the Distillation of Resin obtained from trees A hypergolic propellant is either of the two Rocket propellants used in a hypergolic Rocket engine, which spontaneously ignite when they come into contact e. , self-igniting).

Concentrated nitric acid dyes human skin yellow due to a reaction with the keratin. The skin is the outer covering of living tissue of an animal (or plant Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds These yellow stains turn orange when neutralized. ^[5]

References

1. ^ Nitric Acid
2. ^ BOMARC Summary
3. ^ Standard Methods for the Examination of Water and Wastewater, 20 edition,APHA, AWWA, WEF, 1998
4. ^ http://books.google.com/books?id=CMJvfh2IUSYC&printsec=frontcover&dq
5. ^ Nitric Acid - MOTM November 2007 - HTML only version

External links

• International Chemical Safety Card 0183
• NIOSH Pocket Guide to Chemical Hazards
• European Chemicals Bureau
• National Pollutant Inventory - Nitric Acid Fact Sheet
• Properties and classification of nitric acid