Author Topic: Short Questions Thread  (Read 10826 times)

Shake

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Re: Short Questions Thread
« Reply #820 on: April 23, 2011, 07:14:16 PM »
i am going to do both pyramid, i shall report back with the results, if it doesnt work, i will be on pump number 3

and the aspirator, ill make one because you are right, it will strip dcm and take it straight down the sink which will be handy

letters

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Re: Short Questions Thread
« Reply #821 on: April 23, 2011, 07:29:46 PM »
shake another efficient way to protect the oil pump is to build a hybrid type pumping station.
you take your oil pump, connect it to your system. where you would normally fill the oil you connect to the inlet of a diaphragm pump. the diaphragm pump evacuates the oil chamber which removes any vapors as they reach the oil compartment. i use it often and it works well.

Shake

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Re: Short Questions Thread
« Reply #822 on: April 23, 2011, 07:32:45 PM »
OH i get you now, just remove the vapours as they are sucked in... yes this is a good idea aswell.. what do you think about the carbon filter idea letters?

i have a couple with me just last night i took one apart and poured solvent into it, nothing came out the other side.. this wasnt even vapour!

with the gas masks there are no ifs or buts, there must be NOTHING let through to our lungs.. so they are over over kill as you could imagine
« Last Edit: April 23, 2011, 07:37:00 PM by Shake »

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Re: Short Questions Thread
« Reply #823 on: April 23, 2011, 07:37:27 PM »
yes, you first start your oil pump, then your diaphragm pump, and distill as normal. the diaphragm pump is there to evacuate the oil chamber so it is at the end of the line.

Shake

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Re: Short Questions Thread
« Reply #824 on: April 24, 2011, 07:32:55 PM »
Hey guys i have a question.

Just recently i have been rethinking what 50% NaOH solution means.

Is this - 1kg water to .5kg NaOH OR 1KG of water to 1KG NaOH??

it has to be 1kg water to .5kg NaOH

i was only thinking, if you were to make up 1kg, you put .5kg NaOH and .5kg H2O  which would be 50% NaOH and 50% water.

yes retarded question i know but you see where im coming from?
« Last Edit: April 24, 2011, 07:44:24 PM by Shake »

Vesp

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Re: Short Questions Thread
« Reply #825 on: April 24, 2011, 07:46:33 PM »
It would be 500 grams of water to 500 grams of NaOH to make one kilogram of 50% sodium hydroxide.

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it has to be 1kg water to .5kg NaOH
No No no.... If you were to do 1kg of water to 500 grams of NaOH, your mass would be 1.5 kilograms and be at 33.33% NaOH and 66.66% H2O

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RoidRage

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Re: Short Questions Thread
« Reply #826 on: April 24, 2011, 07:58:52 PM »
Depends if it's 50% mass/mass or mass/volume...


50% NaOH normally means 50% m/v, which is 50g NaOH per 100ml...which is 500g per liter/kilo water

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Re: Short Questions Thread
« Reply #827 on: April 24, 2011, 08:08:49 PM »
Hi, I am trying to extract some paracetamol/acetaminophen to try and make some p-benzoquinone for a wacker oxidation. (http://www.sciencemadness.org/talk/viewthread.php?tid=8250#pid146548)
I couldn't find anywhere how it should be extracted so I made up a solubility table of the binders and excipients in the pills along with their solubility in the solvents I have available. The table is attached. I decided to wash the crushed pills with DCM first to try and remove some of the stuff such as povidone and stearic acid that might cause it to form a goop. I then decide to recrystallize the paracetamol from boiling water leaving the Croscarmellose Sodium in solution, unfortunatly I forgot all about the gelatinised starch and it formed a big mush of goop. Silly me!

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Starch 1500 can be hydrated with cold water to produce viscous slurries or, alternately, can be added directly to the granulator bowl and water can be utilized to granulate. - http://www.colorcon.com/products/core-excipients/immediate-release/starch-1500
Producing viscous slurries is not something I wanna hear!

Anybody know how I could successful purify this? These pills are the most basic I can find in my area, all the other ones have colorings or coating to make them easier to swollow.

Thanks a lot and sorry if I am asking alot of questions lately, I don't expect to be spoonfed but I really don't know where to go here. Thanks!

Vesp

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Re: Short Questions Thread
« Reply #828 on: April 24, 2011, 08:12:46 PM »
Depends if it's 50% mass/mass or mass/volume...


50% NaOH normally means 50% m/v, which is 50g NaOH per 100ml...which is 500g per liter/kilo water

Oh I was thinking mass/mass since the water was originally given in a mass quantity as well as opposed to liters...

Ha! tricky I guess...
The standard is m/v though so it must be 50grams to 100ml of water...
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RoidRage

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Re: Short Questions Thread
« Reply #829 on: April 24, 2011, 08:20:31 PM »
Depends if it's 50% mass/mass or mass/volume...


50% NaOH normally means 50% m/v, which is 50g NaOH per 100ml...which is 500g per liter/kilo water

Oh I was thinking mass/mass since the water was originally given in a mass quantity as well as opposed to liters...

Ha! tricky I guess...
The standard is m/v though so it must be 50grams to 100ml of water...

Actually your intentions were honest since it was indeed given as a mass of water and not volume  ;D...However, I'm pretty positive (but not 100% sure! ) that the standard notation for aqueous solutions is mass/volume .

Shake

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Re: Short Questions Thread
« Reply #830 on: April 25, 2011, 04:36:16 AM »
i used mass because from what i have seen chemists arnt often speaking in volumes, 'so to speak' you use "mills of ketone" and you get labled a cook!

now if 1L water and .5kg NaOH makes 50% NaOH Solution then

what about adding .6kg NaOH to .5kg water i guess you get 110% NaOH solution!

even though it is only a little over half actually sodium hydroxide and half water

 
« Last Edit: April 25, 2011, 04:41:58 AM by Shake »

RoidRage

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Re: Short Questions Thread
« Reply #831 on: April 25, 2011, 04:46:28 AM »
i used mass because from what i have seen chemists arnt often speaking in volumes, 'so to speak' you use "mills of ketone" and you get labled a cook!

now if 1L water and .5kg NaOH makes 50% NaOH Solution then

what about adding .6kg NaOH to .5kg water i guess you get 110% NaOH solution!

even though it is only a little over half actually sodium hydroxide and half water

 

As I said, I think mass/volume notation is standard when speaking about aqueous solutions!

Not the same thing with your ketone example, as density isn't equal to 1.000...On top of that, ketone is used as a reagent, so it's more convenient to speak about mass than volume, especially to calculate moles needed! That's the way I see it

Vesp

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Re: Short Questions Thread
« Reply #832 on: April 25, 2011, 04:59:48 AM »
Chemists use molarity and molality not percent. :)

500 grams in 1L is like 12.5 molar solution?

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RoidRage

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Re: Short Questions Thread
« Reply #833 on: April 25, 2011, 05:00:58 AM »
Chemists use molarity and molality not percent. :)

500 grams in 1L is like 12.5 molar solution?




Yes...so much less confusion using molarity :D

atara

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Re: Short Questions Thread
« Reply #834 on: April 25, 2011, 06:16:27 AM »
I'm used to seeing masses of reactants and volumes of solvents. It's how things are most easily measured and it makes stoichiometry more convenient.

Shake

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Re: Short Questions Thread
« Reply #835 on: April 25, 2011, 08:15:48 AM »
thankyou guys, i am just gonna learn stoichiometry, there will be some initiative shown.


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shroomedalice

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Re: Short Questions Thread
« Reply #836 on: April 25, 2011, 09:04:25 AM »
if only one could buy things per mole at the local store.

honestly two measurements two kinds of thinking.


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Re: Short Questions Thread
« Reply #837 on: April 25, 2011, 08:30:22 PM »
Hey, there is probabaly some obvious answer to this question. I'm just wonder is it possible to isomerise safrole using an equimolar amount of NaOH rather than the standard KOH. I'd assume there would be a reduction in yeild, but would it still isomerise? Sorry if this is a stupid questions!

Methyl Man

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Re: Short Questions Thread
« Reply #838 on: April 26, 2011, 12:39:02 AM »
Is there a way---NOT using an aspirator and sink---to safely and effectively deal indoors with the odors/vapors coming off of a hexamine/HCl hydrolysis from the output tubing from the vac pump?

I'm envisioning something like the output tubing bubbling into a 5-gallon bucket with some kind of solution that absorbs and neutralizes any smelly vapors.

Or better still, can one just do something like running an extension off the tubing down into the toilet past the bend (trap) where the water in the sewer line will absorb it? Not quite sure how that works.
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psychexplorer

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Re: Short Questions Thread
« Reply #839 on: April 26, 2011, 01:48:51 AM »
Bubble (very well) the output vapors through an acid solution. The MeAm(g) will salt out and dissolve.

The gas which inevitably doesn't bubble into solution can be sent through a carbon scrubber or just straight outside, down the drain, etc., if you use a closed bubbler.

I wouldn't dump a ton of raw MeAm(g) down the sewer. It won't stay down there. Keep it away from your neighbors.
« Last Edit: April 26, 2011, 01:51:25 AM by psychexplorer »