He Perchloric acid Is a very strong mineral acid, usually found as a colorless and odorless, corrosive aqueous solution for metals and fabrics.
It is a potent oxidizer when hot, but its aqueous solutions (up to about 70% by weight) at room temperature are generally safe, showing only strong acid characteristics and no oxidizing properties.
Launch of Ares-1 (02 02-2008)
Perchloric acid and its salts (particularly ammonium perchlorate [NH 4 ClO 4 , CAS: 7790-98-9], sodium perchlorate [NaClO 4 , 7601-89-0], and potassium perchlorate [KClO 4 , 7778-74-7), find many applications due to their strong oxidizing power.
Its production has increased due to its use as a starting material for the production of pure ammonium perchlorate, a basic ingredient of explosives and solid propellants for rockets and missiles.
60% perchloric acid
Perchloric acid is also used, on a limited scale, as a reagent for analytical purposes.
Container closed containers may rupture violently under prolonged exposure to heat.
Formulas : Perchloric acid: HClO 4
CAS : 7601-90-3
2D structure
Perchloric acid
3D structure
Perchloric acid / Molecular model of balls and rods
characteristics Of perchloric acid
Physical and chemical properties
| Perchloric acid | |
| Appearance: | Colorless liquid |
| Odor: | toilet |
| Molecular weight: | 100,454 g / mol |
| Boiling point: | 19 ° C |
| Melting point: | -112 ° C |
| Density: | 1.768 g / cm 3 |
| Water solubility | Miscible |
| Acidity (pKa): | -15.2 (± 2.0) |
Perchloric acid belongs to the group of strong oxidizing acids.
Inflammability
- Strong oxidizing acids are generally not flammable, but can accelerate the combustion of other materials by providing oxygen (acting as oxidizing agents).
- Perchloric acid solutions may explode due to heat or contamination.
- When heated above 160 ° C, or are involved in a fire, they may decompose explosively.
- They can react explosively with hydrocarbons (fuels). It can ignite fuels (wood, paper, oil, clothing, etc.).
- Containers may explode when heated.
- Runoff may create a fire or explosion hazard.
Reactivity
- Strong oxidizing acids are generally soluble in water with the release of hydrogen ions. The resulting solutions have a pH of 1 or about 1.
- The materials in this group react with chemical bases (eg amines and inorganic hydroxides) to form salts. These neutralization reactions occur when the base accepts hydrogen ions that the acid donates.
- Neutralizations can generate dangerously large amounts of heat in small spaces.
- The addition of water to the acids often generates enough heat in the small region of the mixture to boil that part of the water explosively, and very dangerous acid splashes may occur.
- These materials have a significant capacity as oxidizing agents, but that capacity varies from one to another.
- They can react with active metals (such as iron and aluminum) and also with many less active metals, to dissolve the metal and release hydrogen and / or toxic gases.
- Their reactions with cyanide salts and their compounds release hydrogen cyanide gas.
- Flammable and / or toxic gases are also generated by their reactions with weak or strong dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides and reducing agents.
- Additional gas-generating reactions occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2) and even carbonates: carbon dioxide gas of the latter is non-toxic but heat and splashes of the reaction may be upset.
- Perchloric acid solutions are strong oxidizing acid solutions.
- They can react vigorously or detonate when mixed with oxidizable materials (alcohols, amines, boranes, dicyanogen, hydrazines, hydrocarbons, hydrogen, nitroalkanes, powdered metals, silanes and thiols, among others).
- The perchloric acid is ignited on contact with sulfinyl chloride.
Toxicity
- Strong oxidizing acids are corrosive to tissues. Acid vapors irritate sensitive tissues (such as the eyes and respiratory system) severely.
- Inhalation, ingestion or contact (of skin, eyes, etc.) with solutions of perchloric acid or its vapors or may cause serious injury, burns or death.
- Contact with fire may produce irritating, corrosive and / or toxic gases.
- Runoff from fire control or dilution water may cause contamination.
Applications
- Perchloric acid is used in the areas of scientific research and development, and in the manufacture of chemicals, electrical, electronic and optical equipment.
- It is used as a precursor in the production of pure ammonium perchlorate, a basic ingredient of explosives and solid propellants for rockets and missiles.
- Uses of perchloric acid in the home include toilet, metal and drain cleaners, rust removers, on batteries and as a primer for false nails.
- Industrial uses include: metal refining, plumbing, bleaching, engraving, electroplating, photography, disinfection, ammunition, fertilizer manufacturing, metal cleaning and rust removal.
- Perchloric acid is also used, on a limited scale, as a reagent for analytical purposes.
Clinical effects
Acids cause coagulation necrosis. Hydrogen ions dehydrate the epithelial cells, causing edema, erythema, tissue detachment and necrosis, with formation of ulcers and bedsores.
In exposure to these acids by the gastrointestinal tract, patients may develop grade II burns (superficial blisters, erosions and ulcerations) which are at risk of subsequent stenosis, particularly the gastric and esophagus.
Deep burns and necrosis of the gastrointestinal mucosa can also develop.
Complications often include perforation (esophageal, gastric, rarely duodenal), fistula formation (tracheoesophageal, aortoesophageal) and gastrointestinal bleeding.
Exposure by inhalation may cause dyspnoea, pleuritic chest pain, cough and bronchospasm, upper respiratory tract edema and burns. Upper respiratory tract edema is common and often life threatening.
Ocular exposure may produce severe conjunctival irritation and chemosis, corneal epithelial defects, limbic ischemia, permanent loss of vision and in severe cases of perforation.
Exposure to mild dermal can cause irritation and partial thickness burns. Longer exposure or high concentration may cause full thickness burns.
Complications may include cellulitis, sepsis, contractures, osteomyelitis, and systemic toxicity.
Safety and risks
Hazard statements of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS)
The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is an internationally agreed system, created by the United Nations and designed to replace the various classification and labeling standards used in different countries through the use of globally consistent criteria.
The hazard classes (and their corresponding GHS chapter), classification and labeling standards, and recommendations for perchloric acid are as follows (European Chemicals Agency, 2017, United Nations, 2015, PubChem, 2017):
GHS Hazard Statements
H271: May cause fire or explosion; Strong oxidizer [Danger Oxidising liquids; Oxidizing Solids - Category 1] (PubChem, 2017).
H290: May be corrosive to metals [Corrosive Warning for Metals - Category 1] (PubChem, 2017).
H302: Harmful if swallowed [Warning Acute toxicity, oral - Category 4] (PubChem, 2017).
H314: Causes severe skin burns and eye damage. [Danger Skin corrosion / irritation - Category 1A, B, C] (PubChem, 2017).
H318: Causes serious eye damage [Danger Serious eye damage / eye irritation - Category 1] (PubChem, 2017).
H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure - Category 2] (PubChem, 2017).
Caution Codes Codes
P301 + P330 + P331, P303 + P361 + P353, P304 + P340, P305 + P351 + P338, P306 + P360, P309 + P311, P310, P321, P330, P363, P370 + P378, P371 + P380 + P375, P390, P404, P405, and P501 (PubChem, 2017).
(United Nations, 2015, p.359).
(United Nations, 2015, p.366).
(United Nations, 2015, p.371).
(United Nations, 2015, p.381).
(United Nations, 2015, p.394).
References
- European Chemicals Agency (ECHA). (2016). Perchloric acid. Brief Profile. Recovered on February 08, 2017, from: echa.europa.eu.
- European Chemicals Agency (ECHA). (2017). Summary of Classification and Labeling. Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation). Perchloric acid...%. Recovered on February 08, 2017, from: echa.europa.eu.
- Hazardous Substances Data Bank (HSDB). TOXNET. (2017). Perchloric acid. Bethesda, MD, US: National Library of Medicine. Retrieved from: toxnet.nlm.nih.gov.
- JSmol (2017) Perchloric acid. [Image] Retrieved from: chemapps.stolaf.edu.
- United Nations (2015). Globally Harmonized System of Classification and Labeling of Chemicals (SGA) Sixth Revised Edition. New York, USA: United Nations publication. Retrieved from: unece.org.
- NASA (2008) Ares-1 launch 02-2008 [image] Retrieved from: commons.wikimedia.org.
- National Center for Biotechnology Information. PubChem Compound Database. (2017). Perchloric Acid - PubChem Structure. [Image] Bethesda, MD, US: National Library of Medicine. Retrieved from: pubchem.ncbi.nlm.nih.gov.
- National Oceanic and Atmospheric Administration (NOAA). CAMEO Chemicals. (2017). Chemical Datasheet. Perchloric acid, with more than 50% but not more than 72% acid. Silver Spring, MD. EU; Retrieved from: cameochemicals.noaa.gov.
- National Oceanic and Atmospheric Administration (NOAA). CAMEO Chemicals. (2017). Chemical Datasheet. Perchloric acid, with more than 50% acid. Silver Spring, MD. EU; Retrieved from: cameochemicals.noaa.gov.
- National Oceanic and Atmospheric Administration (NOAA). CAMEO Chemicals. (2017). Reactive Group Datasheet. Acids, Strong Oxidizing. Silver Spring, MD. EU; Retrieved from: cameochemicals.noaa.gov.
- Oelen, W. (2011) Perchloric acid 60 percent [image] Retrieved from: en.wikipedia.org.
- Vogt, H., Balej, J., Bennett, J.E., Wintzer, P., Sheikh, S.A., Gallone, P.,... Pelin, K. (2000). Chlorine Oxides and Chlorine Oxygen Acids. In Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA. Doi.org.
- Wikipedia. (2017). Perchloric acid. Retrieved February 08, 2017, from: en.wikipedia.org.
- Wikipedia. (2017). Perchloric acid. Retrieved February 08, 2017, from: en.wikipedia.org.