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Order of a calculation
trimmed your middle management
Dec 23, 2016 09:02
7 yrs ago
1 viewer *
English term

eq.

English Law/Patents Chemistry; Chem Sci/Eng chemical patents
To a solution of N-(tert-Butoxycarbonyl)-L-valine (8.06 g, 37.1 mmol, 1.5 eq.) in anhydrous ACN (60 mL) was added carbonyldiimidazole (6.01 g, 37.1 mmol, 1.5 eq.).

To a solution of 293-5 (500 mg, 775.37 µmol) in pyridine (5 mL) was added hydroxylamine hydrochloride (215.5 mg, 3.10 mmol, 4.00 eq.) in one portion at 0 °C under N2.

Question
What does eq. stand for? I appreciate your help. Thanks.
Responses
5 +7 eq.
3 milligrams, millimols, milliequivalents
References
eq. = equivalent?
Votes to reclassify question as PRO/non-PRO:

Non-PRO (1): Yvonne Gallagher

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Discussion

Piyush Ojha Dec 23, 2016:
@Asker As Karen Tkaczyk has said, eq stands for 'molar equivalent'. This is very clear in the 2nd example where the quantity of hydroxylamine hydrochloride (3.10 mmol) is exactly four times the quantity of 293-5 (775.37 µmol), i.e. for each molecule of 293-5 (whatever that is) there are four molecules of hydroxylamine hydrochloride, hence 4.00 eq. The situation is a bit more complicated in the first example. For each molecule of N-(tert-Butoxycarbonyl)-L-valine in the mixture, there is exactly one molecule of carbonyldiimidazole because the total quantity of each compound is 37.1 mmol. So why 1.5 eq and not 1.0 eq? My guess is that the quantity of reactants is being compared with the quatiry of the reaction product, i.e. the reaction produces 37.1/1.5=24.73 mmol of the reaction product.
Muhammad Said (asker) Dec 23, 2016:
Actually, this is my first guess, but I am not sure.
DLyons Dec 23, 2016:
https://en.wikipedia.org/wiki/Equivalent_(chemistry)

Responses

+7
4 hrs
Selected

eq.

This means molar equivalent, i.e. the number of chemical moles of reagent used in each instance. This is basic and obvious to any chemist.
Leave as is in your translations.
Peer comment(s):
agree Piyush Ojha
3 hrs
agree Mikhail Korolev
5 hrs
agree Jennifer Levey
10 hrs
agree acetran
15 hrs
agree Yasutomo Kanazawa
1 day 16 hrs
agree Ashutosh Mitra
1 day 18 hrs
agree writeaway : well, you were here long before the "official" answer
373 days
Something went wrong...
4 KudoZ points awarded for this answer. Comment: "Selected automatically based on peer agreement."
2 hrs

milligrams, millimols, milliequivalents

From Moles to Milliequivalents

Many important substances in the body are measured in equivalents. The technical definition of an equivalent is the amount of substance it takes to combine with 1 mole of hydrogen ions. As an example, we can look at hydrochloric acid (HCl). It takes approximately 35 grams of chloride (1 mole), to combine with 1 gram of hydrogen (1 mole) to make 1 mole of HCl (which weighs approximately 36 grams). Since both of these elements are monovalent (carrying a valence charge with a magnitude of 1), they combine in a one-to-one ratio. Therefore the amount of chloride that is needed to combine with one mole of hydrogen is 1 mole or 1 equilvalent (eq).

http://www.vet.ohio-state.edu/assets/courses/vm613/part7/par...
Peer comment(s):
neutral Jennifer Levey : None of the 3 terms you've given as an answer (mg, mmol and meq.) corresponds to the question as asked. eq. is "equivalent".
12 mins
Something went wrong...

Reference comments

51 mins
Reference:

eq. = equivalent?

Further support for this idea.
Reference:

https://en.wikipedia.org/wiki/Equivalent_concentration

Peer comments on this reference comment:
agree Jennifer Levey
2 hrs
Thank you.
agree Yvonne Gallagher
2 hrs
Thank you.
agree Mikhail Korolev
8 hrs
Thank you.
agree acetran
18 hrs
Thank you.
agree writeaway
374 days
Thank you.
Something went wrong...
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