Question

В 500 мл воды растворено 35,3 г сульфата натрия. Вычислите массовую долю (%) соли в растворе и молярную концентрацию эквивалентов сульфата натрия в приготовленном растворе.

Answer 1

W = (m р.в. * 100%)/m р. = (35,3 г. * 100%)/535,3 г. = 6,6%
m р. = m H20 + m р. в. = 500 г. + 35,3 г. = 535,3 г.
С(1/2 Na2SO4) = (m р. в. * z)/(Mr р. в. * V р.) = 
V p. = m p./ P p. = 
Как видите, молярную концентрацию эквивалента невозможно найти, так как не хватает данных, а именно плотности полученного раствора. Ну хотя бы половина ответа есть.)

Answer 2

Mass Fraction of Salt in the Solution:

To calculate the mass fraction of salt in the solution, we can use the formula:

Mass Fraction (%) = (mass of solute / total mass of solution) x 100

Given that 35.3 g of sodium sulfate is dissolved in 500 ml of water, we can calculate the mass fraction as follows:

Mass of solute (sodium sulfate) = 35.3 g Total mass of solution = mass of water + mass of solute

The mass of water can be calculated using the density of water, which is approximately 1 g/ml. Therefore, the mass of water is 500 g.

Now, we can calculate the total mass of the solution and then the mass fraction of the salt in the solution.

Molar Concentration of Sodium Sulfate in the Prepared Solution:

To calculate the molar concentration of sodium sulfate in the prepared solution, we can use the formula:

Molar concentration (mol/L) = (number of moles of solute / volume of solution in liters)

Given the molar mass of sodium sulfate (Na2SO4) is approximately 142.04 g/mol, we can calculate the number of moles of sodium sulfate in the solution using the mass of sodium sulfate and then use it to find the molar concentration.

Let's calculate both the mass fraction of the salt in the solution and the molar concentration of sodium sulfate in the prepared solution.