Convert concentrations

[ValeryOchkov]

Is the calculation correct? V1+V2 is not equal Vmixture

[ViktorKorobov]

"Defect volume" is reduced if more accurate values for the density to use.

Viktor

[HarveyHensley]

It appears to be correct. The solution density is not linear (i.e. non-ideal) so the volumes don't add. I made some changes to the program because for some unknown reason the symbolic solution for mass and omeaga would not solve. However, I got your answer.

[Werner_E]

because for some unknown reason the symbolic solution for mass and omeaga would not solve.

This is because (on contrary to the solve function in a solve block) the symbolic returns a 1x2 matrix and not a 2x1 matrix. So you would have to change the LHS accordingly. Its an exception, too, that Mathcad will tolerate different units in a matrix here.

[HarveyHensley]

Werner Exinger wrote:

because for some unknown reason the symbolic solution for mass and omeaga would not solve.

This is because (on contrary to the solve function in a solve block) the symbolic returns a 1x2 matrix and not a 2x1 matrix. So you would have to change the LHS accordingly. Its an exception, too, that Mathcad will tolerate different units in a matrix here.

What you saw was my attempt to fix that problem. Valery originally had it the way you say. It still won't work as shown in the attached. It's weird because the answers are shown to the right of the symbolic arrow, but they can't be used below.

[Werner_E]

Harvey Hensley wrote:

It still won't work as shown in the attached. It's weird because the answers are shown to the right of the symbolic arrow, but they can't be used below.

Not sure what's not working for you.

Do you mean you you are not seeing this

[HarveyHensley]

No, this is what I see.

[Werner_E]

Harvey Hensley wrote:

No, this is what I see.

Thats weird indeed. Is it because we use different versions of Mathcad - a bug which was fixed? Im using Mathacd 15 M020.

[HarveyHensley]

Werner Exinger wrote:

Thats weird indeed. Is it because we use different versions of Mathcad - a bug which was fixed? Im using Mathacd 15 M020.

Probably. I'm still on M0005.

[Werner_E]

In the "Read This First" of M020 I find an error which was fixed already in M010 which I think could fit in here

"1412775: Fixes a problem with symbolic calculation of a single line definition and evaluation combined with units"

Link to the RTF: http://www.ptc.com/appserver/wcms/standards/fileothumbredirect.jsp?&im_dbkey=151848&icg_dbkey=522&lang=de

Werner

[HarveyHensley]

Thanks for looking into that error, Werner. You may wonder why I haven't upgraded to M020. The short answer is that I didn't renew my maintenance when I was invited to join the PTC Author program because membership was to include enhanced technical support. However, I never signed the "author" agreement because it would not allow me to use any upgrades in my work! PTC is however, continuing (very slowly) to develop the dll linking to the Prode Physical Properties program. Of course, that should also benefit PTC as I see it.

Another reason is that I couldn't see paying for several versions of Prime that were inferior compared to Mathcad 15.

[Werner_E]

I can perfectly understand that decision of yours.

PTCs business model is somewhat incomprehensible in many parts.

[ValeryOchkov]

Only by m1=m2 (M1=M2) V1+V2=Vmix

[HarveyHensley]

Harvey Hensley wrote:

It appears to be correct. The solution density is not linear (i.e. non-ideal) so the volumes don't add. I made some changes to the program because for some unknown reason the symbolic solution for mass and omeaga would not solve. However, I got your answer.

Correction. It's not the lack of linearity of the density. It's due to the non constant density.

[ValeryOchkov]

Thanks to all!

I think The solution density is a function of a concentration (linear or not linear) so the volumes don't add.

To be or not to be - linear or not linear too

See http://twtmas.mpei.ac.ru/mas/Worksheets/C_NaCl.mcd

And the second.

It will be good to create a function of density with universal argument - a titre (mg/mL), mass ratio, molarity or molality. Mathcad must itself feel what an argument is. It is possible do only in Prime not in old good Mathcad. Or?

[ValeryOchkov · Accepted solution]

40 ml athanol + 60 ml water is not equal 100 ml vodka

But here we have not only a function of density

It is (see bellow) one compliment from me to Harvey

Виктор Иванович, третьим будете! Или Вернера приглашать?

[ViktorKorobov]

Valery Ochkov wrote:

Виктор Иванович, третьим будете! Или Вернера приглашать?

Всегда готов!

[ValeryOchkov]

Valery Ochkov wrote:

It will be good to create a function of density with universal argument - a titre (mg/mL), mass ratio, molarity or molality. Mathcad must itself feel what an argument is. It is possible do only in Prime not in old good Mathcad.

It works in Prime (sorry 3.0 - can you open in 2.0) but not in 15:

[ValeryOchkov]

Only in Mathcad Prime 2.0 and 3.0

[ValeryOchkov]

One more variant:

[Werner_E]

It works in Prime (sorry 3.0 - can you open in 2.0)

You can open it in Prime 0.2, but you will be presented with an empty sheet, so its useless to post sheets in Prime 0.3 format unless you are after a very limited target audience.

Mathcad Prime 0.2 cannot write in MC15 format and cannot read Mathcad 15 files naturally - you would have to install a full fledged MC15 to be able to to the conversion. Thats ridiculous enough. But who would have thought that PTC could make things even worse? Prime 0.3 is not able to save in P0.2 format either!?? That really makes me speechless (well, almost, at least).

[ValeryOchkov]

Werner Exinger wrote:

Mathcad Prime 0.2 cannot write in MC15 format and cannot read Mathcad 15 files naturally - you would have to install a full fledged MC15 to be able to to the conversion. Thats ridiculous enough. But who would have thought that PTC could make things even worse? Prime 0.3 is not able to save in P0.2 format either!?? That really makes me speechless (well, almost, at least).

I hope that final version of Prime 3 will can save as Prime 2.

I am waiting for Mathcad Prime 15

[Werner_E]

Valery Ochkov wrote:

Werner Exinger wrote:

Mathcad Prime 0.2 cannot write in MC15 format and cannot read Mathcad 15 files naturally - you would have to install a full fledged MC15 to be able to to the conversion. Thats ridiculous enough. But who would have thought that PTC could make things even worse? Prime 0.3 is not able to save in P0.2 format either!?? That really makes me speechless (well, almost, at least).

I hope that final version of Prime 3 will can save as Prime 2.

I am waiting for Mathcad Prime 15

Me too. Would be Prime 1.5 according to my numbering (perceived vs. marketed version).

[ValeryOchkov]

Solution of Solutions with Mathcad Prime 3.0 user template: