Gru
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What is meant by 'parts'?
An old procedure calls for amounts in 'parts'.
What is meant by this?
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Jackson
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If it is “equal parts of __ to __” it means equal ammounts of the chemicals
If it is “2 parts of __ per 1 part of __ “ it means a ratio of 2:1 of the chemicals
It is hard until we know what the procedure is and the way it was worded
What is the procedure and what book is it from?
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Gru
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Just found this,
What does the term "part" mean? https://www.chemicalforums.com/index.php?topic=2241.0
Here is the experimental
Example 2 Transformations of nitroketones into their corresponding aminoalcohols
Solution 1
Nickel sulphate 80 parts
Water 600 parts
Solution 2
Isonitrosoacetophenone 200 part
Regular NH3 2670 parts
KOH 35% 120 parts
Shake solution 1 then add in one shot, 600 parts Zinc powder. 15 to 30 minutes later, start adding solution 2 keeping the temperature below 60-70
celsius. The addition should take 2-3 hours. The solution is left stirring for a few more hours. The solution is centrifuged to separate the zinc
precipitate. The precipitate is washed several times with 250 parts distilled water. The washes are added to the solution separated by centrifugation
as above. Potassium carbonate is added in sufficient quantity to extract the base just formed. After washing the extracted base, it can be reacted
with sulphuric acid in the usual conditions to yield the sulphate salt. The yield starting with 200 parts of nitroketones is around 90% of theoric
following the reaction
C6H5COCNOH-CH2 + 6H+ = C6H5COHCNH2CH2
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Jackson
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Solution 1 is a mixture of water and nickel sulphate in a ratio of 600:80
Solution 2 is a mixture of isonitrosoacetophenone, NH3, and a 35 percent solution of KOH in a ratio of 200:2670:120
Basically a part can be whatever measurement you want, writing it in parts makes it so that it is easily scaled
If we say 1 part is a gram the first solution is 600 grams of water and 80 grams of Nickel sulfate
The second solution is 200 grams of isonitrosoacetophenone 2670 grams NH3 and 120 grams of a 35% solution of KOH
You would add 600 grams of zinc powder to solution 1 in this case
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Ubya
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Quote: Originally posted by Jackson  | Solution 1 is a mixture of water and nickel sulphate in a ratio of 600:80
Solution 2 is a mixture of isonitrosoacetophenone, NH3, and a 35 percent solution of KOH in a ratio of 200:2670:120
Basically a part can be whatever measurement you want, writing it in parts makes it so that it is easily scaled
If we say 1 part is a gram the first solution is 600 grams of water and 80 grams of Nickel sulfate
The second solution is 200 grams of isonitrosoacetophenone 2670 grams NH3 and 120 grams of a 35% solution of KOH
You would add 600 grams of zinc powder to solution 1 in this case |
it could be misleading, what if for liquids 1 part is equal to a volume and not a mass? it's more common to say 120ml of a solution vs 120g of a
solution
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feel free to correct my grammar, or any mistakes i make
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Jackson
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I know im just trying to be consistent
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macckone
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With water 1g is approximately the same as 1ml.
In older literature 'part' generally means weight when dealing with solids and volume when dealing with liquids.
When you are mixing the two assuming 1g = 1ml is usually ok.
1 oz weight is also approximately 1 oz liquid.
Some experiments may require more accuracy and then liquid measure was usually avoided.
But a lot of old literature is not very accurate.
[Edited on 11-10-2018 by macckone]
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Tsjerk
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When making for example 100 ml 10% KOH you first weigh 10 grams KOH and then add water to 100 ml, this is important because the density is not 1
gram/ml. You can't add 90 ml of water, as this wouldn't result in 10 % w/v KOH.
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karlos³
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Ah, now it makes much more sense to me they use this many parts of NH3, this stuff from Gru originates in an old patent(1941) and they mean of course
NH4OH solution, in that document usually 20%.
Which density means in that example it equals to 3000ml(almost), making that a rather "round" number.
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macckone
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Tsjerk:
In the older literature you see the 'parts'.
New literature will specifically say ml or grams.
We know density can differ.
You have to read this older stuff especially prior to 1900 to understand the 'parts'.
Karlos:
My guess is they topped it off to 3000 ml.
With ammonia solutions, you have to hope a concentration is mentioned.
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