Difference between revisions of "Iodoform"

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| pKa =  
 
| pKa =  
 
| pKb =  
 
| pKb =  
| Solubility = 0.1 g/L
+
| Solubility = 0.01 g/100 ml
| SolubleOther = Soluble in glacial [[acetic acid]], [[benzene]], [[carbon disulfide]], [[chloroform]]<br>Slightly soluble in [[glycerol]], olive oil, [[petroleum ether]]
+
| SolubleOther = Soluble in glacial [[acetic acid]], [[benzene]], [[carbon disulfide]], [[chloroform]], [[diethyl ether]]<br>Slightly soluble in [[glycerol]], olive oil, [[petroleum ether]]
 
| Solvent1 = diethyl ether
 
| Solvent1 = diethyl ether
| Solubility1 = 136 g/L
+
| Solubility1 = 13.6 g/100 ml
 
| Solvent2 = acetone
 
| Solvent2 = acetone
| Solubility2 = 120 g/L
+
| Solubility2 = 12 g/100 ml
 
| Solvent3 = ethanol
 
| Solvent3 = ethanol
| Solubility3 = 78 g/L
+
| Solubility3 = 7.8 g/100 ml
 
| Solvent =  
 
| Solvent =  
 
| VaporPressure =  
 
| VaporPressure =  
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Iodoform reacts with [[silver nitrate]] to yield [[carbon monoxide]].
 
Iodoform reacts with [[silver nitrate]] to yield [[carbon monoxide]].
  
: AgNO<sub>3</sub> + CHI<sub>3</sub> → AgI + CO + I<sub>2</sub> + ½ N<sub>2</sub> + ½ O<sub>2</sub> + ½ H<sub>2</sub>
+
: AgNO<sub>3</sub> + CHI<sub>3</sub> → AgI + CO + I<sub>2</sub> + ½ N<sub>2</sub> + O<sub>2</sub> + ½ H<sub>2</sub>
  
 
Iodoform can be reduced with [[hydrogen iodide]] to diiodomethane:
 
Iodoform can be reduced with [[hydrogen iodide]] to diiodomethane:
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===Physical===
 
===Physical===
Triiodomethane is a pale yellow, crystalline, volatile substance, with a penetrating and distinctive odor, reminiscent of hospitals, due to its use as a desinfectant. It is practically insoluble in water, but soluble in organic solvents such as chloroform, diethyl ether.  
+
Triiodomethane is a pale yellow, crystalline, volatile substance, with a very strong penetrating and distinctive odor, reminiscent of hospitals, due to its use as a desinfectant. It is practically insoluble in water, but soluble in organic solvents such as [[acetone]], [[benzene]], [[chloroform]], [[diethyl ether]].  
  
 
==Availability==
 
==Availability==
Iodoform is sold in pharmacies, either as a powder or as ether solution.
+
Iodoform is sold in pharmacies, either as a powder or as [[diethyl ether|ether]] solution. Vet shops also carry it.
  
Angel's bonnets naturally produce a small amount of iodoform, which gives their characteristic smell, but extracting it may not be practical.
+
Iodoform in pure form can be bought from lab suppliers or online.
 +
 
 +
Angel's bonnets naturally produce a small amount of iodoform, which gives their characteristic smell, but extracting it may not be practical, as you will need lots of them.
  
 
==Preparation==
 
==Preparation==
 
Iodoform can be prepared very easy via the [[haloform reaction]], by reacting [[iodine]], [[sodium hydroxide]] with a ketone, such as [[acetone]]. As iodoform is practically insoluble in water, the suspension is filtered and then air dried.
 
Iodoform can be prepared very easy via the [[haloform reaction]], by reacting [[iodine]], [[sodium hydroxide]] with a ketone, such as [[acetone]]. As iodoform is practically insoluble in water, the suspension is filtered and then air dried.
  
A less known route involves passing [[iodine]] vapors with steam over red hot coals. The resulting product is purified.<ref>http://gallica.bnf.fr/ark:/12148/bpt6k6137757n/f2.image</ref>
+
A less known route involves passing [[iodine]] vapors with steam over red hot coals. The resulting product is purified via distillation, though if the coal used impurities, many other side products will also be produced.<ref>http://gallica.bnf.fr/ark:/12148/bpt6k6137757n/f2.image</ref>
  
 
Reacting chloroform with calcium iodide at 100 °C yields iodoform.<ref>Spindler; Justus Liebigs Annalen der Chemie; vol. 231; (1885); p. 272</ref>
 
Reacting chloroform with calcium iodide at 100 °C yields iodoform.<ref>Spindler; Justus Liebigs Annalen der Chemie; vol. 231; (1885); p. 272</ref>
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*Antiseptic
 
*Antiseptic
 
*Make diiodomethane
 
*Make diiodomethane
 +
*Strong smelling compound collecting
  
 
==Handling==
 
==Handling==
 
===Safety===
 
===Safety===
Iodoform is irritant and should be handled with care. It's used as an antiseptic in medicine, so protection should be worn when handling the compound.
+
Iodoform is irritant and should be handled with care. Most people find its strong odor obnoxious, so work must be done in well ventilated areas, and never indoors as the odor is quite persistent.
 +
 
 +
Since CHI<sub>3</sub> is used as an antiseptic in medicine, proper protection like gloves and coat should be worn when handling the compound.
  
 
===Storage===
 
===Storage===
In glass bottles, away from light and if possible, air.
+
CHI<sub>3</sub> must be kept in amber glass bottles, bottles with a PTFE seal are recommended to limit its escape, preferably away from light and if possible, air. Do not use plastic, as iodoform will irreversible stain it, especially if in contact with air (elemental iodine is formed) and absolutely never in metal containers.
  
 
===Disposal===
 
===Disposal===
Can be neutralized with a strong base.
+
Can be neutralized with a strong base. This gives sodium iodide which can be recycled, as it's a source of iodine.
  
 
==References==
 
==References==
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*[http://www.sciencemadness.org/talk/viewthread.php?tid=66052 Iodoform problem]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=66052 Iodoform problem]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=56272 Iodoform (Haloform Reaction) Complete Video]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=56272 Iodoform (Haloform Reaction) Complete Video]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=83054 Competition: Idoform (or iodoform even)]
  
 
[[Category:Chemical compounds]]
 
[[Category:Chemical compounds]]
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[[Category:Readily available chemicals]]
 
[[Category:Readily available chemicals]]
 
[[Category:Easily prepared chemicals]]
 
[[Category:Easily prepared chemicals]]
 +
[[Category:Irritants]]
 
[[Category:Solids]]
 
[[Category:Solids]]

Latest revision as of 16:57, 13 April 2019

Iodoform
Names
IUPAC name
Triiodomethane
Preferred IUPAC name
Triiodomethane
Other names
Carbon triiodide
Properties
CHI3
Molar mass 393.73 g/mol
Appearance Yellowish powder
Odor Saffron-like
"Hospital"-like
Density 4.008 g/cm3
Melting point 119 °C (246 °F; 392 K)
Boiling point 218 °C (424 °F; 491 K)
0.01 g/100 ml
Solubility Soluble in glacial acetic acid, benzene, carbon disulfide, chloroform, diethyl ether
Slightly soluble in glycerol, olive oil, petroleum ether
Solubility in diethyl ether 13.6 g/100 ml
Solubility in acetone 12 g/100 ml
Solubility in ethanol 7.8 g/100 ml
Thermochemistry
180.1–182.1 kJ·mol−1
Hazards
Safety data sheet AcrosOrganics
Flash point 204 °C
Lethal dose or concentration (LD, LC):
355 mg/kg (oral, rat)
1180 mg/kg (dermal, rat)
1.6 mmol/kg (s.c., mouse)
Related compounds
Related compounds
Chloroform
Bromoform
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Iodoform is a yellowish organoiodine compound with the formula CHI3.

Properties

Chemical

Iodoform reacts with silver nitrate to yield carbon monoxide.

AgNO3 + CHI3 → AgI + CO + I2 + ½ N2 + O2 + ½ H2

Iodoform can be reduced with hydrogen iodide to diiodomethane:

CHI3 + HI → CH2I2 + I2

Physical

Triiodomethane is a pale yellow, crystalline, volatile substance, with a very strong penetrating and distinctive odor, reminiscent of hospitals, due to its use as a desinfectant. It is practically insoluble in water, but soluble in organic solvents such as acetone, benzene, chloroform, diethyl ether.

Availability

Iodoform is sold in pharmacies, either as a powder or as ether solution. Vet shops also carry it.

Iodoform in pure form can be bought from lab suppliers or online.

Angel's bonnets naturally produce a small amount of iodoform, which gives their characteristic smell, but extracting it may not be practical, as you will need lots of them.

Preparation

Iodoform can be prepared very easy via the haloform reaction, by reacting iodine, sodium hydroxide with a ketone, such as acetone. As iodoform is practically insoluble in water, the suspension is filtered and then air dried.

A less known route involves passing iodine vapors with steam over red hot coals. The resulting product is purified via distillation, though if the coal used impurities, many other side products will also be produced.[1]

Reacting chloroform with calcium iodide at 100 °C yields iodoform.[2]

Projects

  • Antiseptic
  • Make diiodomethane
  • Strong smelling compound collecting

Handling

Safety

Iodoform is irritant and should be handled with care. Most people find its strong odor obnoxious, so work must be done in well ventilated areas, and never indoors as the odor is quite persistent.

Since CHI3 is used as an antiseptic in medicine, proper protection like gloves and coat should be worn when handling the compound.

Storage

CHI3 must be kept in amber glass bottles, bottles with a PTFE seal are recommended to limit its escape, preferably away from light and if possible, air. Do not use plastic, as iodoform will irreversible stain it, especially if in contact with air (elemental iodine is formed) and absolutely never in metal containers.

Disposal

Can be neutralized with a strong base. This gives sodium iodide which can be recycled, as it's a source of iodine.

References

  1. http://gallica.bnf.fr/ark:/12148/bpt6k6137757n/f2.image
  2. Spindler; Justus Liebigs Annalen der Chemie; vol. 231; (1885); p. 272

Relevant Sciencemadness threads