Question

А) Сколько надо добавить воды к 40л 80%-го спиртового раствора, чтобы он стал 60%-ым ? б) Сколько надо добавить воды к 40л 90%-го спиртового раствора, чтобы он стал 80%-ым ?​

Answer 1

Ответ:

Пошаговое объяснение:

90-80=10%

40л 90%

Хл 10%

Х=40×10÷90=4,44л

Answer 2

Calculation of Water Addition to Alcohol Solutions

To calculate the amount of water that needs to be added to a given volume of alcohol solution to achieve a desired concentration, we can use the following formula:

Amount of Water to be Added = (Final Concentration - Initial Concentration) / (Final Concentration) * Initial Volume

Let's calculate the amount of water needed for the two scenarios mentioned:

a) To make a 40L 80% alcohol solution into a 60% solution: - Initial Concentration = 80% - Final Concentration = 60% - Initial Volume = 40L

Using the formula, we can calculate the amount of water to be added:

Amount of Water to be Added = (60% - 80%) / (60%) * 40L

Calculating this expression, we find that 16.67L of water needs to be added to the 40L 80% alcohol solution to make it a 60% solution.

b) To make a 40L 90% alcohol solution into an 80% solution: - Initial Concentration = 90% - Final Concentration = 80% - Initial Volume = 40L

Using the formula, we can calculate the amount of water to be added:

Amount of Water to be Added = (80% - 90%) / (80%) * 40L

Calculating this expression, we find that 5L of water needs to be added to the 40L 90% alcohol solution to make it an 80% solution.

Please note that these calculations assume that the volumes are additive and that the alcohol and water are miscible in all proportions.