The Creation Wiki is made available by the NW Creation Network
Watch monthly live webcast - Like us on Facebook - Subscribe on YouTube

Hydrofluoric acid

From CreationWiki, the encyclopedia of creation science
Jump to: navigation, search
Hydrofluoric acid
Example.jpgExample.jpg
General
Other names

fluoric acid
fluorhydric acid

Molecular formula HF
Molar mass Molar mass::20.01 g/mol
Appearance colorless liquid with strong, irritating smell
CAS number CAS number:: 7664-39-3
Properties
Density and phase Density::1.15 g/ml, liquid
Solubility in water miscible
Melting point Melting point::-36.111°C
Boiling point Boiling point::108°C
Acidity (pKa) 3.17
Viscosity 1.2630 cP at 5°C
Structure
Molecular shape Linear
Dipole moment 1.826.178 D
Hazards
MSDS Material safety data sheet
Main hazards corrosive
NFPA 704

NFPA 704 svg.png

0
4
0
ACID
R/S statement R: Corrosive
S: gloves and goggles
Related compounds
Other anions

Hydrochloric acid
Hydrobromic acid
Hydroiodic acid

Related compounds Hydrogen Fluoride
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Disclaimer and references

Hydrofluoric acid is a solution of hydrogen and fluoride in water. It is a precursor to almost all fluorine compounds, including the elemental fluorine itself. It is a colorless solution that is highly corrosive, capable of dissolving many materials, especially oxides. Its ability to dissolve glass has been known since the 17th century, even before Carl Wilhelm Scheele prepared it in large quantities in 1771. Because of its high reactivity toward glass and moderate reactivity toward many metals, hydrofluoric acid is usually stored in plastic containers. Hydrogen fluoride gas is an acute poison that may immediately and permanently damage lungs and the corneas of the eyes. Aqueous hydrofluoric acid is a contact-poison that can have deep, initially painless burns and ensuing tissue death. By interfering with body’s metabolism, the concentrated acid may also cause systemic toxicity and eventual cardiac arrest and fatality, after contact with as little as 25 square inches of skin. [1]

Properties

Its Physical state and appearance is a Liquid. It has a strong odor. It’s a colorless solution made up of water and hydrogen fluoride. It has a density of 1.15 g/ml. its Boiling Point is 108°C (226.4°F) and its Melting Point is -36.111°C (-33°F). Its acidity is 3.17 so it is a weak acid. It’s very hazardous and corrosive to human skin. It is easily soluble in cold water, hot water. Partially soluble in diethyl ether.[2][3]

Synthesis

Hydrofluoric acid is usually made in a factory. It does not occur in nature. It is made from putting Dry Fluorspar (CaF2) and Sulphuric acid (H2SO4) and mixing them in a rotary kiln to create an endothermic reaction. The HF gas is then put in a washing column, then a condenser, then a distillation column. It is turned into Hydrofluoric acid. [4]

Uses

Hydrofluoric acid has a variety of uses in industry and research. It is used as a starting material or intermediate in industrial chemistry, mining, refining, glass finishing, silicon chip manufacturing, and in cleaning. In metalworking, hydrofluoric acid is used as a pickling agent to remove oxides and other impurities from stainless and carbon steels because of its limited ability to dissolve steel. Because of its ability to dissolve most oxides and silicates, hydrofluoric acid is used for dissolving rock samples usually before the analysis. Also, this acid is used in acid maceration to extract organic fossils from the surrounding rocks. The rock with fossils may be immersed directly into the acid, which sticks to the organic component and allows the rock to be dissolved around it. Diluted hydrofluoric acid is used in the petroleum industry in a mixture with other acids, those acids could be HCl or organic acids, in order to stimulate the production of water, oil, and gas wells specifically where sandstone is involved. Hydrofluoric acid is also used by some collectors of antique glass bottles to remove the remaining contents from the glass, caused by acids, usually in the soil the bottle was buried in, attacking the soda content of the glass. Other printing companies use hydrofluoric acid to remove unwanted images from printing plates. Felt-tip markers are available to make the process safer for the worker.[5][6][7]

Bottle of Hydrofluoric acid

Health/Safety

Hydrofluoric Acid is one of the most dangerous acids known. It needs to be treated differently than even strong acids like Sulfuric and Hydrochloric. The Hydrogen Fluoride molecule is so mobile that it may easily pass through the skin. Because Fluorine has an extremely high affinity for Calcium, bones will be attacked, and this may result in hypocalcaemia. There may be no pain immediately after the burn, leading the injured person to believe that they are not in danger. It is so potent that contact with it may not even be noticed until long after serious damage has been done. Even very strong acids, and mixtures of acids do not have the power to cause death and injury in the way that Hydrofluoric Acid can.

Wear personal protective equipment when handling any amount of HF including gloves, goggles, face shield, and a lab coat. HF should always be used in a chemical fume hood.

The contact of concentrated solutions of HF (from 49%) with skin immediately causes severe and painful lesions. Then the damaged area of skin discolors and becomes whitish or grayish at the center, surrounded by a purplish crown. If the time of contact increases, the damaged skin turns to red then to grayish purple/black purple, with an intense pain.[8][9][10]

Video

In this Video the Mythbusters attempt to see if Hydrofluoric acid can be used to melt a body like it dones in the show Breaking Bad.

References

  1. Authorlastname, Firstname. [1] Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  2. Authorlastname, Firstname. [www.dehs.umn.edu/.../HF_Acid_Fact_Sheet.doc site-or-2] Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  3. Authorlastname, Firstname.[http://wcam.engr.wisc.edu/Public/Safety/MSDS/Hydrofluoric%20acid,%2049%25.pdf site-or-3] Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  4. Authorlastname, Firstname. [2] Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  5. Authorlastname, Firstname. site-or-author5 Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  6. Authorlastname, Firstname. site-or-author6 Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  7. Authorlastname, Firstname. site-or-author7 Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  8. Authorlastname, Firstname. site-or-author8 Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  9. Authorlastname, Firstname. [www.dehs.umn.edu/.../HF_Acid_Fact_Sheet.doc site-or-author9] Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)
  10. Authorlastname, Firstname. site-or-author10 Publisher site name. Web. Month Day, Year. (specify whether date of publication or last-modified or accessed - i.e. Published November 3, 2015.)