Hi, does anyone remember how to calculate a final concentration and volume of seawater from two known concentrations of seawater, where one is *not* fresh water.
For example, how to calculate the requisite volumes of seawater at 70 ppt and 30 ppt to produce 7 liters of 50 ppt?
Thank you.
In this case is 50% / 50% (because the final concentration of 50 ppt is (70+30)/2].
But, if you want to calculate (for other and future cases):
V1+V2=7 L -> V2=7-V1
V1*70 + V2*30=7*50
So:
70V1 + 30(7-V1)=350
V1 (70 ppt) = 3.5 L
V2 (30 ppt) = 3.5 L
Thanks Sam. We now have several independent derivations of this system, and we can go back to work with our crabs. Your way is very elegant and straight forward.
The product of concentration by volume is equal to equivalent units N; the Ns of solutions are adjusted to give the wanted concentration.
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