You dissolve the sample of FD&C Red 40 (molar mass 496.4200 g/mol) in enough water to make 250.0 mL of solution. We call this the stock solution.
What is the concentration of the stock solution in terms of molarity?

Question

You dissolve the sample of FD&C Red 40 (molar mass 496.4200 g/mol) in enough water to make 250.0 mL of solution. We call this the stock solution.
What is the concentration of the stock solution in terms of molarity?

anonymous · Answer

$$Molarity=\frac{ mol solute }{ volume }$$
mol solute in grams
volume in liters.

anonymous · Answer

Molarity in M

cooltowl · Answer

so I divide the molar mass or Red 40 by 250 ml?

anonymous · Answer

FD&C Red 40 is the name of substance being dissolved.
1 sample of it would have 496.420g

cooltowl · Answer

how do I get moles of solute?

cooltowl · Answer

Never mind I got it the answer. I divided 1.833x10^-5/.25

anonymous · Answer

Oh, I think you didnt post more information with this question.
This is part of a series of questions right?

cooltowl · Answer

Yeah Im sorry about that I just realized it when I was trying to solve the problem but thank you. you helped a lot

anonymous · Answer

No wonder.
Just post information that goes with the question next time.
Good luck.

jhannybean · Answer

Yeah, seems like some parts were missing.