Question

СРОЧНО, ПРЯМ ОЧЕНЬ СРОЧНО Задача:В водном растворе было 90 г соли, затем в него добавили еще 120 г воды. После этого концентрация раствора уменьшилась на 6,25%. Вопрос. Какой была изначальная масса воды и концентрация соли в растворе? ПОЖАЛУЙСТА ГЕНИИ ​

Answer 1

Ответ:

270г , 25%

Объяснение:

пусть первоначально воды было х г, концентрация была 9000%/(90+х)

стало: 120+х г воды и концентрация 9000%/(90+120+х)

уравнение: 9000/(90+х)-9000/(210+х)=6,25

Answer 2

Task Analysis

The task requires determining the initial mass of water and the concentration of salt in a water solution. The solution initially contained 90g of salt, to which 120g of water was added. After this addition, the concentration of the solution decreased by 6.25%.

Initial Mass of Water Calculation

To calculate the initial mass of water, we can use the fact that the concentration of the solution decreased by 6.25% after adding 120g of water.

Concentration of Salt in the Solution

The concentration of salt in the solution can be calculated using the initial mass of water and the initial mass of salt.

Solution

Let's proceed with the calculations.

Initial Mass of Water Calculation

The decrease in concentration after adding 120g of water can be used to calculate the initial mass of water.

The decrease in concentration is 6.25%, which can be represented as 0.0625 in decimal form.

The initial mass of water can be calculated using the formula: Initial Mass of Water = (Amount of Water Added) / (Decrease in Concentration)

Substituting the values: Initial Mass of Water = 120g / 0.0625 Initial Mass of Water = 1920g

The initial mass of water was 1920g.

Concentration of Salt in the Solution

The concentration of salt in the solution can be calculated using the initial mass of water and the initial mass of salt.

The initial concentration of the solution can be calculated using the formula: Initial Concentration = (Mass of Salt) / (Total Mass of Solution)

Substituting the values: Initial Concentration = 90g / (90g + 1920g) Initial Concentration = 90g / 2010g Initial Concentration ≈ 0.0448 or 4.48%

The initial concentration of salt in the solution was approximately 4.48%.