LuckyWinner
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Diethyl Ether - Keep on failing to make it -Errors
ethanol 95%
sulfuric acid 95%
were placed in a freezer overnight.
Next morning (freezer cooled)
ethanol 24ml is added into a 250ml erlenmeyer flask in an icebath.
sulfuric acid 20ml is slowly dripped in with magnetic stirring.
after addition, simple distillation is set up with a spiral cooler and ice water
(2 ice packs inside tap water). this ice water is getting pumped
through the spiral condenser with a 12v pump.
erlenmeyer flask is placed on ceramic lab hot plate with 5g of acid wash sand.
(this sand was prepared by heating beach sand in 20%HCL solution for 1 hour,
washed in water then reheated on hotplate for 1hour at max temperature)
Erlenmeyer flask is heated slowly till the temperature that measures the reaction liquid
shows 140C.
-SHOULD YOU MAGNETIC STIRR THIS SOLUTION with the acid wash sand or NOT?
the claisen adapter is covered in condensate, tiny droplets.
tiny droplets of distillate form at the spiral condenser and then quickly stop to condense.
temp at condenser is ~40c , when adding ethanol climbs to 50-55C
reaction liquid bubbles heavy , a black foam creeps up to the top of the erlenmeyer
when adding ethanol.
all videos and texts say you should add ethanol 95% by additional funnel into
the main liquid by a glass rod that is submerged to avoid superheating he ethanol
by just dripping it on top of the solution.
I did that and still didnt get anything...
what is the error?
I watched 5 diethyl ether video, nilred, chemx,...
and read the illustrated diethyl ether guide other threads.
nobody mentions these issues.
Suggested solution:
illustrated diethyl ether guide
1.
When excess EtOH is added to the mixture in (1) and heated to 140C ether if formed and H2SO4 regenerated - it thereby acts as a catalyst. If no excess
ethanol is added, the ethyl bisulphate remains stable to about 160C when it starts eliminating H2SO4 and generating ethylene C2H4.
A: Since there is only a 4ml difference between my sulfuric acid and ethanol ratio,
that means I get 4ml of distillate from the mother liquid and if I DONT add any further ethanol
there will be NO FURTHER distillate coming over?
since 4ml is a tiny amount that will not result in any droplets coming into the receiving flask
there will be no visual indicator for when to turn on the additional funnel
[Edited on 16-8-2020 by LuckyWinner]
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LuckyWinner
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other questions:
1. once ether was made by simple distillation can this ether be stored in a freezer for 1 or more nights, THEN AFTER take out the byproducts , water
and unreacted H2SO4 by sep funnel
sodium bicarb , Nacl washes?
2.you do the simple distillation of ether and complete it.
for how long can the distillation setup stand in the shade without any danger of explosion.
I remember reading ether can explode that is stuck in between the joints.
usually ether should not form explosive peroxides that quickly until its in direct sunlight for a couple days?
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Fyndium
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Strange. When I made ether ages ago, I used normal distillation setup with addition funnel and I remember mixing the starting solution of acid and
ethanol pretty quickly without any refrigeration and just kept the heating bath temp between 140-145C and collected distillate as it produced and
adjusted the ethanol drip rate to distillate drip rate. The whole process took several hours and after I washed it with bicarb and redistilled the
ether, dried it and stored it over a pinch of NaOH.
Ether forms peroxides over time and it is usually stored in aluminum containers stabilized with something commercially. The peroxides are a risk when
concentrating ether by distillation, usually not by themselves because the concentration is so low. Easily avoided with small amount of NaOH.
A higher risk for common chemist is the extreme flammability and low boiling point of ether. It just simply evaporates, floats everywhere and
self-ignites at 160C. I'm actually surprised I never got into any trouble with it when I was young and stupid ages ago, because I always used direct
gas burners to heat everything, including ether, never greased any joints and was just mostly reckless by nature in my experiments.
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LuckyWinner
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Quote: Originally posted by Fyndium  | Strange. When I made ether ages ago, I used normal distillation setup with addition funnel and I remember mixing the starting solution of acid and
ethanol pretty quickly without any refrigeration and just kept the heating bath temp between 140-145C and collected distillate as it produced and
adjusted the ethanol drip rate to distillate drip rate. The whole process took several hours and after I washed it with bicarb and redistilled the
ether, dried it and stored it over a pinch of NaOH.
Ether forms peroxides over time and it is usually stored in aluminum containers stabilized with something commercially. The peroxides are a risk when
concentrating ether by distillation, usually not by themselves because the concentration is so low. Easily avoided with small amount of NaOH.
A higher risk for common chemist is the extreme flammability and low boiling point of ether. It just simply evaporates, floats everywhere and
self-ignites at 160C. I'm actually surprised I never got into any trouble with it when I was young and stupid ages ago, because I always used direct
gas burners to heat everything, including ether, never greased any joints and was just mostly reckless by nature in my experiments.
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thanks and I know all these things...
maybe there is something wrong with my ethanol...
I will make my own , dry with mol sieves and try again.
cant think of any other reason why I cant seem to make ether.
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Fyndium
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What kind of ethanol you are using? It doesn't need to be anhydrous, 95 will work fine, but if it's very diluted or adulterated with something - or
isn't ethyl alcohol at all, then it'd be the issue.
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LuckyWinner
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| Quote: Originally posted by Fyndium | | What kind of ethanol you are using? It doesn't need to be anhydrous, 95 will work fine, but if it's very diluted or adulterated with something - or
isn't ethyl alcohol at all, then it'd be the issue. |
the bottle says just alcohol rectified 96%
it does not mention if its ethyl alcohol, its smells like it...
it can only be ethanol but there may be something wrong with it.
i cant explain why the diethyl ether synthesis does not work out.
I follow the route exactly and tried every variation.
a couple drops always for in the condenser at the beginning but
after a couple minutes they stop forming...
I put a alcohol swimmer inside the ethanol and it says 96%
sulfuric acid is 95% analytical quality.
acid wash sand, is beach sand boiled in 25% HCL , water washed and dried.
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macckone
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140C is when the reaction starts to get usable yield it needs to be higher.
150C is when ethylene starts forming but your product will be mostly ether at that point.
160C you will get significant ethylene.
170C is going to yield straight ethylene gas.
The reaction mixture needs to be higher than 140C.
145C is ideal.
Have you considered your thermometer might be the problem?
And your condenser water temperature needs to be 0C if possible.
It is also possible the ether isn't condensing.
[Edited on 17-8-2020 by macckone]
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kilowatt
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When I made ether I heated the acid up first and dripped in ethanol through an addition funnel. The distillation aparattus had a variable flow reflux
condenser and a main Graham condenser. I don't remember exactly what I used to supply cold fluid to the condensers but probably an ice bath.
I used stainless scrubbers to pack the reflux column (really just a packed Allihn condenser) and it imparted an odd smell, not necessarily into the
product but I noticed it when cleaning it. Today I would use fiberglass patches.
The mind cannot decide the truth; it can only find the truth.
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