Question

Найти массу воды и соли для приготовления 150г 20% раствора

Answer 1

Дано:
m р-ра = 150 г
w р.в. = 20% = 0.2
m (H2O) - ?
m р.в. - ?

Решение:
w р.в. = m р.в/m р-ра * 100%
0.2 = x/150 г * 100%
x = 150 г * 0.2
x = 30 г

m р-ра = m (H2O) - m р.в
m (H2O) = m р-ра - m р.в. = 150 г - 30 г = 120 г

Ответ: m (H2O) = 120 г; m р.в = 30 г.

Answer 2

Дано:
m(р-ра)=150 г    W(в-ва) = m(в-ва) / m(р-ра)  *100%
W(в-ва) = 20%    m(в-ва) = m(р-ра) * W(в-ва) / 100% = 150*20 / 100% = 30 г
Найти:                 m(воды) = m(р-ра) - m(в-ва) = 150 - 30 = 120 г
m(в-ва)
m(воды)

Answer 3

Calculating Water and Salt Mass for a 150g 20% Solution

To calculate the mass of water and salt needed to prepare a 150g 20% solution, we can use the formula for calculating the mass of solute and solvent in a given solution.

Step 1: Calculate the Mass of Salt (Solute) The mass of salt can be calculated using the formula: \[ \text{Mass of salt} = \text{Total mass of solution} \times \text{Percentage of salt} \]

Substituting the given values: \[ \text{Mass of salt} = 150g \times 20\% \]

Using the given values, the mass of salt can be calculated as follows: \[ \text{Mass of salt} = 150g \times 0.20 = 30g \]

Step 2: Calculate the Mass of Water (Solvent) The mass of water can be calculated using the formula: \[ \text{Mass of water} = \text{Total mass of solution} - \text{Mass of salt} \]

Substituting the given values: \[ \text{Mass of water} = 150g - 30g = 120g \]

Therefore, to prepare a 150g 20% solution, you would need 30g of salt and 120g of water.