Solve the problem.
-In a chemistry class, 7 liters of a 4% silver iodide solution must be mixed with a 10% solution to get a 6% solution. How many liters of the 10% solution are needed?
A) 2.5 L
B) 4.5 L
C) 7.0 L
D) 3.5 L

Question

Quizplus · Accepted Answer

To solve this problem, we use the equation for mixture problems: (amount of solute in the first solution + amount of solute in the second solution) / (total volume of solution) = desired concentration. Let x be the liters of the 10% solution needed. The amount of silver iodide in the 7 liters of 4% solution is 0.04 * 7. The amount in the x liters of 10% solution is 0.10 * x. The total volume of the solution is 7 + x liters, and we want a 6% solution, so the equation is: (0.04*7 + 0.10*x) / (7 + x) = 0.06. Solving for x gives x = 3.5 liters.

Solve the Problem. -In a Chemistry Class, 7 Liters of a 4% Silver