# help - (Feb/11/2013 )

Hello.
I have a solution of SBS (sodium bisulphite) 40 % w/w, 1000 L. I want to make this 1.3 % so i can preserve some membranes. i need to dilute this in a tank of 65 000 L of water. What can i do?

-pipo88-

you can't make 65 000 L with 1000 L of 40%. 40% is ~30x 1.3%, you can only make ~ 30 000 L (do you really mean L? that's a lot of solution).

-mdfenko-

yes, is 65000 liter tank. If i need more than 1000L of SBS i can get. The point is what calculations i need to make to estimate how much i need to achieve the concentration of 1.3 %.

-pipo88-

pipo88 on Tue Feb 12 11:32:43 2013 said:

yes, is 65000 liter tank. If i need more than 1000L of SBS i can get. The point is what calculations i need to make to estimate how much i need to achieve the concentration of 1.3 %.

how about using maths rule of three or cross-multiplication......C1V1=C2V2 would work too.....

-casandra-

casandra is correct (i was going to tell you the same but she beat me to it).

c1=40%, c2=1.3%, v2=65 000 L. calculate for v1(the amount of 40% you need to make 65 000 L of 1.3%)

v1=(c2v2)/c1=(1.3*65000)/40=2112.5 L

-mdfenko-

i thought of this. but the density of the solution is different from the water. Doesn't the density play a part in this?

-pipo88-

pipo88 on Wed Feb 13 09:54:26 2013 said:

i thought of this. but the density of the solution is different from the water. Doesn't the density play a part in this?

no, not for this case. it is a simple dilution. try not to overthink the problem.

-mdfenko-