Guide
1
If there are two solution , one with a concentration - and the other - with interest, for the preparation of V milliliters solution given concentration b (provided that band less, but more with), take x milliliters of a percent solution and (V - x) with milliliters per cent solution .Given that a & gt; b & gt; c, compose the equation, from which then find x: s + c • (V - x) = bV, then x = V • (bc) / (ac).
2
If you take over a 0, the previous equation takes the form x = V • b / a, ml.Podstavte required values ​​and solve this equation.So you get, how much of the need to take stock solution to prepare the solution given concentration .
3
for dilution of concentrated solutions use the rule of mixing.For example, for the preparation of b percentage solution take two solution with concentration and with interest, provided that a & gt; b
4
Record the condition and the result is.Please note the concentration prepared solution (b) and diagonally from the bottom up to the right of this value will record one of the answers, which refers to a% solution obtained by the difference between the predetermined concentrations (b-c), and from top to bottom right, record the second answer(a-b), with relation to the% solution.The resulting need to record the answers in front of the respective solutions, ie,in front of x and y.
5
For clarity, to get 30% (x - p-p with conc. And%) and 15% (p-p at a conc. With%) solutions of 20% (b),follow the steps described above: 20-15, and 30-20 = 5 = 10.Thus, for the preparation of a solution of 20% mix 5 parts of 30% solution and 10 parts of 15% solution.The result was a 15 parts of a 20% solution.