Skip to main content

Benzalkonium chloride

Structure of Benzalkonium chloride, source: Wikipedia

Properties

White to white-yellow powder or gelatinous yellowwhite fragments, the compound is hygroscopic, which means it easily attracts water (from f.e. the air).
When the compound gets heated, it will form a clear molten mass.
It is soluble in water and alcohol. When it is resolved in water, the H2O solution will form excessive foam.


How to identify the compound
It
- UV spectrophotometry: maxima at 257 nm, 263 nm and 269 nm.
- Using liquid chromatography
- Adding Na-tetraphenylborate and acetic acid will form a sediment of benzalkoniumtetraphenylborate. Which has a characteristic melting point of 127-133 °C.
- Bringing the compound in a NaOH solution together with BFB (bromephenol blue) and dimethylchloride will form a blue colour in the CH2Cl2 layer. This is caused by the ionpair forming with the anionic pigment (BFB) and extraction of the ionpair in the organic layer.
- Identification of Cl- ions: + AgNO3 will form a white precipitate which is soluble in NH3.
Or if you add dichromate -> chromylchloride will be formed + phenylcarbazide -> white precipitate.



Determining the content

Adding KI in an alkaline environment -> forms benzalkoniumiodide which will be extracted to CH2Cl2 (organic layer).
The excess of the I- ions (in the water layer) will be determined using KIO3 in strong acid (H+ milieu). This is also called the method of Andrews


I- + IO3- -> I+ (jodoxyl)
Intermediate = I2


Use of benzalkonium chloride

It's used as a disinfectant in concentrations of about 0,1% for hands (used in surgery), small wounds, eat and drinking disinfectant, bed sheets, etc.

Comments

Popular posts from this blog

Alkynen: Elektrofiele additie

Elektrofiele additie: Waterstofhaliden op alkynen Voorbeeld van waterstofhaliden: HCl, HBr, HF, HI Gebruik van één equivalent waterstofhalide met alkyn (dus 1:1 geen overmaat geen tekort) Bij een overmaat aan het waterstofhalide zal een tweede reactie plaatsvinden op het gehalogeneerde alkyn, ter vorming van een geminaal regioisomeer.

Coca-Cola: Life - myth or truth?

"Coca-Cola Life" Recently the Coca-Cola company released a new beverage: the Coca-Cola Life drink. It should contain less sugar than the normal Coca-Cola drink; a part of the sugar is replaced with the recently approved sweetener from the Stevia plant (stevioglycosides). It's being sold as a 'natural' drink, but those stevioglycosides are as natural as the chemical sweetener aspartame found in Light and Zero drinks. However it is true that the amount of sugar is much lower (being reported as 33%, some say it's around 20%); yet approximately still 3-4 sugar cubes / 33 cl can (5-6 in a normal can). I bought it myself and found that the flavor has not really changed from the original Coca-Cola, however it does taste more "flat" - but definitely true it yourself. The outside of the can has the colour green. I personally do not associate this "healthy - natural" colour with Coca-Cola, but it's growing on me. In sum

Alkanes and radicals 4: Additionreactions of radicals

Alkanes and radicals Addition of radicals on an alkene Look at the two reactions below, the first reaction is in normal circumstances, which will result in a normal Markovnikov reaction  ( with the addition of a   protic acid  HX to an  alkene , the acid hydrogen (H) becomes attached to the carbon with fewer   alkyl   substituents , and the  halide  (X) group becomes attached to the carbon with more alkyl substituents). In the second reaction, peroxide is used as condition, this will result in an anti-Markovnikov  reaction. The peroxide will generate Br radicals in small amounts (this is the initiation for this anti-reaction).  Let's see the peroxide mechanism in detail. As stated above, an alkyl peroxide is a radical initiator. The electrophile will add on the sp2 carbon which carries the most hydrogens (where also the radical with most alkyl groups will be formed). The termination reactions will have several other outcomes. In the major outcome, the radical will not b