An aqueous solution with sulfur 10 g/L at the rate is 100 L/min and an organic compound with no sulfur at the rate 50 L/min were put into an extraction machine and produced an aqueous solution with sulfur 1 g/L, what is the amount of sulfur in the organic compound after extraction?

Correct Answer: 9 g/L
Let the amount of sulfur in the organic compound be x. Sulfur balance equation, 100(10) + 50(0) = 100(1) + 50(x), => x = 9 g/L.