Question

How many liters (L) of a 10% silver iodide solution must be mixed with 3 L of a 4% silver

iodide solution to get a 6% solution?

Answer 1

Explanation:

Let the litre of silver iodide be x

10% of silver iodide = 10% of x = 0.1x

4% of 3L of silver iodide= 4% of 3 = 0.04 × 3 = 0.12

The resulting mixture is 6% of solution, I.e 6% of (x + 3) = 0.06(x+3) = 0.06x + 0.18

Then,

10% of x + 4% of 3 = 6% of (x + 3)

0.1x + 0.12 = 0.06x + 0.18

0.1x - 0.06x = 0.18 - 0.12

0.04x = 0.06

x = 0.06 / 0.04

x = 1.5L

Then, 1.5L of 10% silver iodide will be added to 3L of 4% silver iodide to give 6% of silver iodide