Question

Обчисліть масу води (г), яку треба додати до 100 г розчину з масовою часткою солі 0,4, щоб одержати розчин із масовою часткою 0,1: А. 300 Б. 200 В. 100 Г. 500 помогите пожалуйста)

Answer 1

Нехай Х маса розчину, тоді(0,2Х):(Х+100)=0,10,1(Х+100)=0,2Х0,1х+10=0,2х10=0,1хх=100

Answer 2

Calculation of the Mass of Water to be Added

To calculate the mass of water that needs to be added to a 100 g solution with a mass fraction of salt of 0.4 in order to obtain a solution with a mass fraction of 0.1, we can use the formula:

Mass of water = (Mass of salt in final solution - Mass of salt in initial solution) / (Mass fraction of water in final solution - Mass fraction of water in initial solution)

Let's plug in the given values:

- Mass of salt in final solution = 0.1 * (100 g + mass of water) - Mass of salt in initial solution = 0.4 * 100 g - Mass fraction of water in final solution = 1 - 0.1 = 0.9 - Mass fraction of water in initial solution = 1 - 0.4 = 0.6

Substituting these values into the formula, we get:

Mass of water = (0.1 * (100 g + mass of water) - 0.4 * 100 g) / (0.9 - 0.6)

Simplifying the equation, we have:

Mass of water = (10 g + 0.1 * mass of water - 40 g) / 0.3

Further simplifying, we get:

Mass of water = (0.1 * mass of water - 30 g) / 0.3

To solve for the mass of water, we can multiply both sides of the equation by 0.3:

0.3 * mass of water = 0.1 * mass of water - 30 g

Simplifying further, we have:

0.2 * mass of water = 30 g

Finally, we can solve for the mass of water:

mass of water = 30 g / 0.2 = 150 g

Therefore, the mass of water that needs to be added to the 100 g solution with a mass fraction of salt of 0.4 in order to obtain a solution with a mass fraction of 0.1 is 150 g.