In a chemistry class 7 Liters of a 4% Iodide solution must be mixed with a 10% solution to get a 6% solution how many liters of a 10% solution are needed

3.5

Step-by-step explanation:

If x is the volume of 10% solution, and y is the volume of 6% solution, then:

x + 7 = y

0.10x + 0.04 (7) = 0.06y

Solve the system of equations.

0.10x + 0.04 (7) = 0.06 (x + 7)

0.10x + 0.28 = 0.06x + 0.42

0.04x = 0.14

x = 3.5

3.5 liters of 10% solution is needed.