How to calculate weight needed for a concentration

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Molar concentration is defined as the number of moles of solute per liter of solution. The discussion centers on calculating the amount of resveratrol needed to achieve a concentration of 5 micromoles per liter in 10 grams of dimethylsulfoxide (DMSO). It clarifies that 5 uM refers to micromoles per liter, and emphasizes the importance of using the correct density of DMSO, which is approximately 1.1004 g/cm³, not its molar mass. A formula is provided to calculate the required grams of resveratrol, highlighting the need to rearrange it for clarity. The conversation also warns about the safe handling of DMSO and the importance of consulting safety data sheets.
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Please post this type of questions in HW section using the template and showing your work.
I haven't had a chemistry class in many years. Recently I saw an interesting article that used a solution of resveratrol (228.25 grams per mole) in dimethylsulfoxide (78.13 grams per mole). The concentration was listed as 5 uMol.
If I had 10 grams of DMSO how much resveratrol would I add to achieve the 5 uMol concentration? And how is this calculated? Thanks.
 
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Start with the definition of molar concentration.
 
Would you be clearer about the "5 uMoL" ? What is that unit? Micro-something. Either you mean, MOLES, MICROMOLES, MICROMOLES-or-LITER, MICROMOLES PER LITER,... What?
 
Borek said:
M usually stands for mol/L, mM and μM are rather common and unambiguous extensions. What is a bit confusing is your way of calling it μMol.
Okay, micromoles per liter.
You want 5 micromoles per liter of resveratrol. You 'have' 10 GRAMS of DMSO and you wish to find how much resveratrol is needed.

Use x grams of resveratrol,
d is density of dimethylsulfoxide as grams per milliliter , which you need to look-up,
and you should fill in the unstated units of measure to be sure you see the way the two numbers work,
and the right side is as MOLES per LITER:
(x(1/228.25))/(10*(1/d)*(1/1000))=0.000005

(Micro moles per liter, the same as the number shown on the right side)
That is in plain text but you could rewrite in normal notation on paper, yourself so more understandable.
Solve for x.

Note: the density of DMSO is NOT 78.13 grams per mole and not moles per liter. See a handbook.

Also, note, https://en.wikipedia.org/wiki/Resveratrol
 
Last edited:
I'd guess that a person should not go playing with dimethylsulfoxide without care and knowledge. Storage? Exposure? Grades of quality? Material Safety Data Sheet?
 
https://en.wikipedia.org/wiki/Dimethyl_sulfoxide
According to Wiki, the density is almost like water at 1.1004 g cm−3.
78.13 is the molar mass, which I thought might have been needed.
Thanks for the formula. I will rearrange it on paper when I get a chance.
Also good to know was that uM means micro-moles per liter. Would not have guessed that.
 

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