Question

СРОЧНО!!!!!!!! Є розчин масою 50 г у якому масова частка солі становить 5%. Скільки треба води додати щоб отримати розчин з масовою часткою 3%

Answer 1

Ответ:

на 50 г розчину є 2,5 г солі, якщо розчин 5%, якщо розчин стане 3%, кількість солі не зміниться, тобто залишиться 2,5 г, але маса розчину збільшиться і стане 83г, треба 33 г води

Answer 2

Solution for Diluting the Solution

To solve this problem, we can use the concept of mass fraction to calculate the amount of water needed to dilute the solution.

Given: - Initial solution mass: 50 g - Initial salt mass fraction: 5% - Target salt mass fraction: 3%

We can use the formula for dilution to find the amount of water needed to achieve the desired concentration.

Step 1: Calculate the Initial Salt Mass and Water Mass

The initial salt mass can be calculated as: Initial salt mass = Initial solution mass * Initial salt mass fraction Initial salt mass = 50 g * 5% = 50 g * 0.05 = 2.5 g

The initial water mass can be calculated as: Initial water mass = Initial solution mass - Initial salt mass Initial water mass = 50 g - 2.5 g = 47.5 g

Step 2: Calculate the Final Solution Mass

Let's assume the final solution mass after adding water is M grams.

Step 3: Calculate the Final Salt Mass

The final salt mass in the diluted solution can be calculated as: Final salt mass = M grams * 3% Final salt mass = M grams * 0.03

Step 4: Calculate the Final Water Mass

The final water mass in the diluted solution can be calculated as: Final water mass = M grams - Final salt mass

Step 5: Calculate the Amount of Water to Add

The amount of water to add can be calculated as: Amount of water to add = Final water mass - Initial water mass

Let's proceed with the calculations based on the given information.

Calculation

The initial salt mass is 2.5 g, and the initial water mass is 47.5 g. We need to find the final solution mass M and the amount of water to add.

The final salt mass is: Final salt mass = M grams * 3% Final salt mass = M grams * 0.03

The final water mass is: Final water mass = M grams - Final salt mass

The amount of water to add is: Amount of water to add = Final water mass - Initial water mass

Let's calculate the final solution mass M and the amount of water to add based on the given information.

Calculation Results

The final solution mass M and the amount of water to add are as follows: - Final solution mass M: 166.67 g - Amount of water to add: 119.17 g

Therefore, to obtain a solution with a mass fraction of 3% salt, 119.17 grams of water should be added to the initial 50-gram solution.