Disposing of haloalkane

[Ophelia]

I have a small amount of a haloalkane that students made by reacting an alcohol with conc. HCl.

Is there a safe way of disposing of it other than what CLEAPSS instructions say? (To be collected by a Registered Waste Carrier)

 

[Deleted member 32724]

I have a small amount of a haloalkane that students made by reacting an alcohol with conc. HCl.

Is there a safe way of disposing of it other than what CLEAPSS instructions say? (To be collected by a Registered Waste Carrier)

If it is a small amount you can pour it in a shallow tray filled with water inside a fume cupboard turned on and let them evaporate.
Otherwise what I do is just have a large bottle only for halogenated organic waste and get that collected every 4-5 years when it gets filled up.

 

[Ophelia]

If it is a small amount you can pour it in a shallow tray filled with water inside a fume cupboard turned on and let them evaporate.
Otherwise what I do is just have a large bottle only for halogenated organic waste and get that collected every 4-5 years when it gets filled up.

Thank you! I’ll speak to my HoD and see what they’d prefer.

 

[Bob Worley]

Well there is a way. Make 50% propanone/water mix at Universal indicator or bromothymol blue. Add a magnetic stirrer. Add the 2-chloro-2-methylpropane and then 2M sodium hydroxide. Just a little so you see that the indicator changes colour as the water reacts with the chloride producing hydrogen ions. Keep adding the alkali until it no longer goes acidic.(You may have to do some maths but a litre of 1M NaOH reacts with about 100 ml of the chloride). It is quite a nice demonstration. It is a SN1 reaction. Not all halogenoalkanes react as easily as this but tertiary halides are the most reactive. CLEAPSS will think further about a problem if you ask them (it means it usually coems to me)..Flush down the foul water drain with lots of water.

 

[Ophelia]

Thank you Bob! I’m going to try evaporating it in a fume cupboard, in an empty classroom. There’s only a few mls.

 

[Ophelia]

Thank you Bob! I’m going to try evaporating it in a fume cupboard, in an empty classroom. There’s only a few mls.

It worked

 

[Mike_N]

Evaporating in a fume hood tends to be my go-to for most of my alcohol based wastes.

 

[007]

I have a small amount of a haloalkane that students made by reacting an alcohol with conc. HCl.

Is there a safe way of disposing of it other than what CLEAPSS instructions say? (To be collected by a Registered Waste Carrier)

I would carry out a nucleophilic substitution reaction and turn it back into an alcohol by using NaOH, the alcohol is easy to dispose of than haloalkanes. Evaporating in a fume cupboard can take some time also if its a mobile fume cupboard you will use up your filter very quickly and they aren't cheap to replace.