[blueberry58]

The process of propionaldehyde given by www.orgsynth.org ( I attached it here) is straightforward and use a 2 litters three necked round bottomed flask to a yield of 44-47 gr of product per process. As I need to get 325 grs of this compound, I'm in doubt between buy and carry a bigger RBF or make do several small reactions of the same process but have access to only four hours to the laboratory and the chemist that can only be with me during that time in the morning.

On the other hand, I do not know if I should change H2SO4 and K2Cr7O7 in each batch or continue serving these compounds. I know this is a silly question but, where may I find information on this kind of production playing with volume and batchs?

Thank you.

Mod edit: Here is the attached text. Dan

Synthtesis of Propionaldehyde
 One hundred grams (125 cc., 1.7 moles) of n-propyl alcohol, b.p. 96–96.6°, is placed in a 2-l. three-necked, round-bottomed flask fitted with a mercury-sealed stirrer (Note 1), a dropping funnel, and a 60-cm. bulb condenser (Note 2) set at an angle of 45°. Water at 60° is kept circulating through this condenser. A condenser set for downward distillation is connected to the top of the first condenser. Cold water circulates through the second condenser. By means of an adapter, the lower end of the second condenser is fitted to a receiver which is cooled with ice water.
The alcohol in the flask is heated to boiling, stirred, and a mixture of 164 g. (0.56 mole) of potassium dichromate, 120 cc. of concentrated sulfuric acid (2.2 moles), and 1 l. of water is added through the dropping funnel. The addition takes about thirty minutes, and during this time the contents of the flask are kept vigorously boiling. After all the oxidizing mixture has been added, the contents of the flask are boiled for fifteen minutes to distil the last of the aldehyde. The propionaldehyde which collects in the receiver is dried with 5 g. of anhydrous sodium sulfate and fractionally distilled. The yield of propionaldehyde boiling at 48–55°, and having a refractive index of 1.364 (Note 3), is 44–47 g. (45–49 per cent of the calculated amount).
2. Notes
1. The yield of propionaldehyde depends largely upon the efficiency of the stirrer.
2. The purpose of the first condenser is to condense and return to the flask any propyl alcohol which escapes.
3. The recorded value for the index of refraction (N20°D) is 1.3636.
3. Discussion
Propionaldehyde has been prepared by passing propyl alcohol over finely powdered reduced copper;1 by passing a mixture of propyl alcohol and air over a hot platinum spiral2 or a silver catalyst containing a small amount of samarium oxide;3 by passing a mixture of steam and propylene oxide over silica gel at 300°;4 by adding propyl alcohol to a dichromate oxidizing mixture5 or adding a dichromate oxidizing mixture to propyl alcohol;6 by heating propylene glycol to 500°;7 by heating a mixture of calcium formate and calcium propionate;8 by the action of ethylmagnesium iodide on amyl formate;9 by catalytic hydrogenation of acrolein;10 by electrolysis of calcium chloride or dilute sulfuric acid solutions of propyl alcohol;11 by passing vapors of propyl alcohol over cadmium oxide at 325°;12 by passing vapors of propionic acid and formic acid over titanium oxide at 250–300°;13 by oxidizing propyl alcohol with a stream of air in the presence of copper bronze, nitrobenzene, and quinoline;14 and by treating ethyl orthoformate with ethylmagnesium bromide.15

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[Dan]

You can probably buy 100 kg of propionaldehyde for the price of the glassware you would need for this. Don't waste time and money, just buy it.

[blueberry58]

Thank you Dan:

Propionaldehide (1000 ml ) prices:

US 30,89
https://us.vwr.com/store/catalog/product.jsp?catalog_number=AAA16146-AU

Colombia USD 83 (with no taxes). Only one purveyor in Bogota.

[discodermolide]

I don't think you should be doing this, even with supervision quote" I do not know if I should change H₂SO₄ and K₂Cr₇O₇ in each batch or continue serving these compounds". It seems as if you have no clue as to what's going on.

Only one supplier in Bogota, if I were you I'd just buy it. Probably safer.

[blueberry58]

I am not chemist. This preparation will be done in a laboratory of a university here in Cali. A student of chemistry of 5th year and above her a chemistry teacher who works developing smart materials are in charge. Perhaps they will choose another way to prepare this. I bring them this information to not arrive with my empty hands. 

[Arkcon]

Well then, I think you do have a fair starting point for discussion with the laboratory manager.  If you want to know if the oxidizing acid needs to be changed, try to work out for your self what the reaction is, and what's being consumed, and in what quantities.  That will also be a worthwhile thing to have to show to the professor.

[blueberry58]

Thank you Arkcon:

My question has a more generical sense.

where may I find information on this kind of production playing with volume and batchs?

The how to lesser batch processes can accomplish the same that bigger volume reactions (obviously in more time).