[tassawar517]

Hello!
I need 2ml of 1Molar-(NH4OH) to add in a solution. But I have 30% concentrated NH3 aqueous solution. So how would I calculate the required amount provided with this solution? And I know the molecular mass and density if needed in the calculations?

[P]

It's been a while...  but don't you convert some of the 30% solution to a 1 Molar solution using a volumetric flask and take 2 ml from that?

[tassawar517]

I need 2ml of 1Molar-NH4OH to add in my solution for a reaction but I don't have exact 1molar-(NH4OH) solution. I have 30% concentrated NH3 aqueous solution and the aqueous solution of NH3 is a similar thing as (NH4OH). But I am having a problem that since the molecular weight of NH4OH is different from that of NH3 and I also don't know the exact molarity of 30% concentrated NH3 solution. So, how I gonna convert or calculate the amount of solution which should be equal to 2ml of 1Molar NH4OH.

[P]

I seem to remember my chem teacher telling us to break it down to first principles every time when working out molarity questions. You are counting the exact number of molecules you have using Avagadro and working out how much you have to add to a volumetric to get the concentration you want when you make the solution up to the exact volume. You can then take your 2 ml from the standard solution you make.

I hope that helps. I probably don't have time to do the question for you....  but break it down to first principles  - you are literally counting the amount of atoms you have in the flask or per unit volume. You can then work it up to the volume/concentration you require and take out 2 ml from that stock solution.

[Borek]

Everything you need to know about converting concentrations and diluting solutions:

http://www.chembuddy.com/?left=concentration&right=toc