Solve the problem.
-In a chemistry class, 9 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) 9 L
B) 5.5 L
C) 4.5 L
D) 3.5 L

Question

Quizplus · Accepted Answer

To solve this problem, we use the concept of weighted averages or the method of alligation. The amount of silver iodide in the 9 liters of 4% solution is 0.04 * 9 = 0.36 liters. Let x be the liters of the 10% solution needed. The total amount of silver iodide in the final solution is 0.36 + 0.10x liters, and the total volume of the solution is 9 + x liters. We want a 6% solution, so the equation is (0.36 + 0.10x) / (9 + x) = 0.06. Solving for x gives x = 4.5 liters.

Solve the Problem. -In a Chemistry Class, 9 Liters of a 4% Silver