Question 823410
Bleach now come in a 8.5% concentration. I want to make 500ml of a 10% bleach solution using the 8.5% concentration. Need ot know the amount of bleach needed. 
-------------
You are going to have to add some bleach solution that is more
than 10%.
I'll assume you have a 100% solution available for the mixture.
--------------------
active + active = active
0.085x + 1*(500-x) = 0.10*500
-----
85x + 1000*500 - 1000x = 100*500
-----
-915x = -900*500
x = 491.8 ml (amt. of 8.5% solution needed)
500-x = 8.2 ml (amt. of 100% concentrate needed)
====================
Cheers,
Stan H.
====================