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acetic acid solution

Posted: Tue Mar 23, 2021 1:56 pm
by sue
Calculate the ml that need to be transferred from a solution of 950ml CH 3 COOH at 48% by mass with a density of 1.05g / ml to prepare a solution at 1.28M in 250ml.

i dont understand :cry:

Re: acetic acid calculation

Posted: Tue Mar 23, 2021 2:06 pm
by ChenBeier
Calculate backward how many moles is 1,28 M in 250 ml, this convert with the molar mass of acetic acid to the mass. This value dilute to 48 % and with the density you get the required volume.

Re: acetic acid solution

Posted: Tue Mar 23, 2021 4:58 pm
by sue
mmmmm thank you ?

Re: acetic acid solution

Posted: Wed Mar 24, 2021 1:47 am
by ChenBeier
What is wrong, what you dont understand. Start with the first one.
What is meant with 1.28 M

Re: acetic acid solution

Posted: Thu Mar 25, 2021 3:25 am
by Dhamnekar Winod
If i am correct , 145.12 ml that need to be transferred from the solution of 950 ml of CH3COOH at 48% by mass with a density of 1.05 g/ml to prepare solution of 1.28 M in 250 ml.

Re: acetic acid solution

Posted: Thu Mar 25, 2021 4:43 am
by ChenBeier
Wrong result

Re: acetic acid solution

Posted: Thu Mar 25, 2021 5:12 am
by Dhamnekar Winod
I edited my answer from 152.5 ml to 145.12 ml. Is this correct?

Re: acetic acid solution

Posted: Thu Mar 25, 2021 5:14 am
by ChenBeier
No, show your calculation. But normaly Sue should do it.

Re: acetic acid solution

Posted: Thu Mar 25, 2021 6:08 am
by Dhamnekar Winod
Here is my computational chemistry work

We have 950 ml of solution of CH3COOH.
The density of this solution is 1.05g/ml. CH3COOH is present 48% by mass in this solution. Mass of 950 ml of solution is 950 ml *1.05g= 997.50 g.

CH3COOH is 0.48 of 997.50 g. = 478.80 g. Molar mass of CH3COOH is 60.0524g/gmol. 478.8g/60.0524 g = 7.973 M of CH3COOH is present in 950 l of solution.

So, in 250 ml of its solution ,2.098 M of CH3COOH is present.

But we want to prepare solution of 1.28 M. Hence, we require \(152.51 ml =\frac{ 250 ml*2.098M}{1.28 M}\) needs to betransferred from 950 ml of solution of CH3COOH

Re: acetic acid solution

Posted: Thu Mar 25, 2021 7:17 am
by ChenBeier
No that was not the question.
A solution of 250 ml 1.28 M should be prepared.
250 ml contain 1/4 = 0.32 mol. This calculated with the molar mass of 60 g/mol gives 19,2 g 100% what is equal 40 g 48%. With Density of 1.05 g/ ml it gives 38 ml.

Re: acetic acid solution

Posted: Thu Mar 25, 2021 8:46 am
by Dhamnekar Winod
Thanks for your correct answer.