Question

К 250 гр умножить на 20% раствора naoh прибавим 20 г чистого naoh какова массовая доля naoh в полученном растворе

Answer 1

Было:
m(рра)=250г
ω(вва) = 20%
m(вва)=50г


Стало:
m(рра)=250 + 20 = 270г
m(вва)=50 + 20 = 70г
ω(вва) = (70 * 100)/270 ≈ 25,9 ≈ 26%
Ответ: 26%

Answer 2

Calculation of the Mass Fraction of NaOH in the Solution

To calculate the mass fraction of NaOH in the solution, we need to consider the initial mass of the solution and the mass of pure NaOH added.

Given: - Initial mass of the solution: 250 g - Concentration of the NaOH solution: 20%

First, we need to calculate the mass of NaOH in the initial solution. We can do this by multiplying the initial mass of the solution by the concentration of NaOH:

Mass of NaOH in the initial solution = Initial mass of the solution * Concentration of NaOH

Using the given values: Mass of NaOH in the initial solution = 250 g * 20% = 50 g

Next, we need to calculate the total mass of the solution after adding 20 g of pure NaOH. The total mass of the solution will be the sum of the initial mass of the solution and the mass of pure NaOH added:

Total mass of the solution = Initial mass of the solution + Mass of pure NaOH added

Using the given values: Total mass of the solution = 250 g + 20 g = 270 g

Finally, we can calculate the mass fraction of NaOH in the resulting solution. The mass fraction is the ratio of the mass of NaOH to the total mass of the solution:

Mass fraction of NaOH = Mass of NaOH in the resulting solution / Total mass of the solution

Using the calculated values: Mass fraction of NaOH = 50 g / 270 g ≈ 0.1852

Therefore, the mass fraction of NaOH in the resulting solution is approximately 0.1852 or 18.52%.

Please note that the search results did not provide specific information regarding the mass fraction of NaOH in the resulting solution. The calculation provided above is based on the given information and general principles of solution concentration.