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Heating solvent

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StrangeLoop

StrangeLoop

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Now I know the general procedure followed is to boil water and remove it from heat and place the solvent in a jar in the hot water bath. I was curious as to what the danger is of using an electric glasstop stove to directly heat the solvent? In lab we always use flameless heat sources because of the flammability danger but we will usually directly heat solvents even to boiling using a hot plate. So are we just overly cautious when it comes to home cookin?
 
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SWIM managed to ignite naphtha with a hand mixer and almost burn down his basement. Earlier, he managed to ignite some naphtha while trying to evaporate it in an electric oven. The oven managed to keep the flames from spreading, but the smoke was toxic and awful. Conclusion: don't mess around with flammable solvents.
 
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How do you ignite it with a hand mixer? :?

And I can totally see it igniting in an oven. Enclosed space + heat from all sides = flame on! I'm not sure how this applies to heating it from the bottom on an electric stove...but better safe than sorry I suppose.
 
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Heat it on a water bath with good ventillation. Eg heat a pot of water, which heats your vessel of solvent. Beware a lot of electric hotplates spark and can ignite vapors. You can hear these plates arc/click and see the flash underneath.
 
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Ever heard of flash boiling? (when a liquid is rapidly forced into its vapor state)

I thought not.. Try putting water in a jar and heating it up on your electric stove, Youll see what happens pretty fast. You so dont want naptha to boil everywhere.

Just stick to the "overly" safe method. Its proven, it works, it works well.

-gir
 
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have a glass top electric stove - am going to be using it for evaporation in a bit, used it earlier but it smells too much and it's a communal kitchen...waiting til everyone goes to sleep.

Will be creating a water bath, not directly heating a naptha container.
 
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Hope you've still got eyebrows jblazing ... you know it's really not that hard just to let it evaporate at room temperature. It really only takes a few hours with enough surface area.
 
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^ really?? I'm sure most of the time it could go OK, but what about the exception? I'd rather not risk it.

KinkyJohn (love the name hehe) - yo, I would never use a microwave, glasstop hob is the furthest I would go to heating solvents - man it took a while though...
 
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xtechre, you're right, SWIM was an idiot, you absolutely have to respect these chemicals... He is embarrassed to even admit on here as such stupid stuff is obviously exactly what any serious kitchen chemist warns against... I only mention it, lest anyone ever forget, flammable solvents are flammable.
 
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dg said:
jblazingnataraja said:
^ mmm almost as much as someone suggesting it be put in the microwave...
Click to expand...

have seen xylene and tolulene zapped to remove emulsions in cacti extractions many, many times
Click to expand...

not a good method for heating the solvent, though.
microwaves are tuned for vibrational excitation of compounds with dipole moments, namely water. most nonpolars have no strong dipole interactions.
it's much better to heat the water bath in the microwave, then put the solvent in
 
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I have found that the solvents with high vapor pressure and volatility are to be respected as well even when warmed only using hot water. If in a closed container pressure can build fast and shatter separation funnels or other containers. I once was using 35/60 petroleum ether in an extraction and fortunately it only blew the stopper out of my separation funnel. The stopper flew 3 feet into the air and loudly crashed into the sink. Because it was really quiet at 3AM in my house, it scared the crap out of me. Fortunately there was no breakage of my glassware.
 
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benzyme said:
dg said:
jblazingnataraja said:
^ mmm almost as much as someone suggesting it be put in the microwave...
Click to expand...

have seen xylene and tolulene zapped to remove emulsions in cacti extractions many, many times
Click to expand...

not a good method for heating the solvent, though.
microwaves are tuned for vibrational excitation of compounds with dipole moments, namely water. most nonpolars have no strong dipole interactions.
it's much better to heat the water bath in the microwave, then put the solvent in
Click to expand...


no its not good for heating, which is why i said it had been used to clear emulsions,
 
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I have my glass of solvent in a pot with hot water on the ceramic hotplate, when the glass starts to rumble because of the boiling water i move from plate and then reapply the pot to the plate until boiling occurs again. When the glass is in the pot and on the hotplate i have glass covered with paper towel and i press the glass gently down so as to stop the rumbling of the glass. Do this a few times over maybe 5- 10 minutes and your naptha will be as hot as you want it.
 
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