Question

解5道关于浓度的应用题 快 1.把100克食盐加水稀释成浓度为5%的盐水 与要加水多少克?2.往浓度为10%,重量为30

Answer 1

1.加水X克：

100 / (100 + X) = 5%

解得X = 1900

2.加X克水：

(300 * 10%) / (300 + X) = 8%

解得X = 345

3.((500 * 70%) + (300 * 50%)) / (300 + 500) = 62.5%

4.10 / (10 + 100) = 9.09%

5.蒸发X克水：

(10 * 10%) / (10 - X) = 20%

解得X = 5