Question 275411
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In a chemistry class, 6 liters of 4% silver iodide solution must be mixed with 10% solution to get a 6% solution. 
How many liters of 10% solution are needed?
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<pre>
Let x be the volume (in liters) of the 10% silver iodide solution to add.


Write the balance equation for solute (silver iodide)

    0.04*6 + 0.1x = 0.06*(6+x).


Simplify and find x

    0.24 + 0.1x = 0.36 + 0.06x,

    0.1x - 0.06x = 0.36 - 0.24,

        0.04x    =     0.12

            x    =     0.12/0.04 = 3.


<U>ANSWER</U>.  3 liters of the 10% silver iodide solution should be added.
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Solved correctly.