Question

К двадцатипроцентному раствору щёлочи добавили 25 кг щёлочи, в результате чего концентрация раствора стала равна 36%. Найдите массу полученного раствора.

Answer 1

Решение смотри на фото

Answer 2

Calculation of the Mass of the Solution

To find the mass of the resulting solution, we need to use the given information about the concentration of the solution before and after adding 25 kg of the alkali.

Let's assume the initial mass of the solution was M kg, and the concentration of the solution before adding the 25 kg of alkali was 20%. After adding the 25 kg of alkali, the concentration of the solution became 36%.

We can set up the following equation to solve for the initial mass of the solution:

M * 20% + 25 kg = M * 36%

To solve this equation, we can follow these steps:

1. Convert the percentages to decimal form: 20% = 0.20 and 36% = 0.36. 2. Distribute the percentages: 0.20 * M + 25 kg = 0.36 * M. 3. Subtract 0.20 * M from both sides of the equation: 25 kg = 0.16 * M. 4. Divide both sides of the equation by 0.16: M = 25 kg / 0.16.

Now, let's calculate the value of M:

M = 25 kg / 0.16 = 156.25 kg

Therefore, the mass of the resulting solution is 156.25 kg.