Question

Срочно!! до 170 г розчину калій нітрату з масовою часткою солі 15% долили 30 мл води. Знайдіть масову частку солі в новоутвореному розчині. 2. Скільки грамів чистої води необхідно взяти для приготування 420 г розчину з масовою часткою солі 0,8%?

Answer 1

Ответ:

1. Масовая частка соли: 12,4%.

1. Масовая частка соли: 12,4%.2. Для 420 г раствора с масовой часткой соли 0,8% - 3,36 г воды.

Думай!

Answer 2

Calculation of Mass Fraction in a Solution

To find the mass fraction of salt in the newly formed solution, we can use the formula:

Mass Fraction = (Mass of Salt / Total Mass of Solution) * 100%

In the first scenario, we have a 170 g solution of potassium nitrate with a mass fraction of salt of 15%. We add 30 ml of water to this solution.

To find the mass fraction of salt in the new solution, we need to calculate the mass of salt and the total mass of the solution.

1. Calculation of the mass of salt: - Mass of salt = Mass fraction of salt * Total mass of solution - Mass of salt = 15% * 170 g = 0.15 * 170 g = 25.5 g

2. Calculation of the total mass of the solution: - Total mass of solution = Mass of salt + Mass of water - Mass of water = Volume of water * Density of water - Since the density of water is approximately 1 g/ml, the mass of water is equal to its volume. - Mass of water = 30 ml = 30 g

- Total mass of solution = Mass of salt + Mass of water - Total mass of solution = 25.5 g + 30 g = 55.5 g

3. Calculation of the mass fraction of salt in the new solution: - Mass fraction of salt = (Mass of salt / Total mass of solution) * 100% - Mass fraction of salt = (25.5 g / 55.5 g) * 100% ≈ 45.95%

Therefore, the mass fraction of salt in the newly formed solution is approximately 45.95%.

Calculation of the Mass of Water in a Solution

In the second scenario, we need to determine the mass of water required to prepare a 420 g solution with a mass fraction of salt of 0.8%.

To find the mass of water, we can use the formula:

Mass of Water = Total Mass of Solution - Mass of Salt

1. Calculation of the mass of salt: - Mass of salt = Mass fraction of salt * Total mass of solution - Mass of salt = 0.8% * 420 g = 0.008 * 420 g = 3.36 g

2. Calculation of the mass of water: - Mass of water = Total mass of solution - Mass of salt - Mass of water = 420 g - 3.36 g = 416.64 g

Therefore, to prepare a 420 g solution with a mass fraction of salt of 0.8%, you would need approximately 416.64 g of water.

Please note that these calculations assume ideal conditions and do not account for any potential losses during the mixing process.