[forgottenformula]

Hey guys, im no student, however, the answer to this would be quite practical for my work at the hospital...

I have 250ml of 0,9% sodium chloride saline. I also have several 20ml ampoules of 6% sodium chloride saline. How many ampoules of 20ml do I need to add to the 250ml 0,9% saline to get a saline of 3% sodium chloride?


How do I calculate it the proper way? What is the formula? I tried it, it was about 9 ampoules if im not mistaken... Thx for the *delete me*

[AWK]

9 is OK

[forgottenformula]

thx, I know 9 are ok, but for other concentrations id like to have a formula or something to find the solution faster.

[AWK]

The formula is called - mass balance.

[forgottenformula]

Can you pls elaborate and show me how to calculate it tho? Or is it too complicated?

[AWK]

https://www.chembuddy.com/?left=concentration&right=dilution-mixing
In your case, you can assume, with an error of less than 5%, that the volumes of the solutions and the masses are approximately equal (i.e. that the salt solutions have the density of water). For more accurate calculations, you need to know the temperature of the solutions and their densities.
https://primerdigital.com/tools/UniDilution.html