Question

Смешали 43 г 25%-ного раствора гидроксида натрия и 81 г 40%-ного раствора того же гидроксида. Вычислите массовую долю NaOH в полученном растворе.​

Answer 1

Ответ:

34,79%

Объяснение:

Общая масса гидроксида

m(NaOH)=43*0.25+81*0.4=43,15

Общая масса раствора

m(Р-р)=43+81=124

Массовая доля

W(NaOH)=43.15/124=0,3479 или 34,79%

Answer 2

Calculating the Mass Fraction of NaOH in the Solution

To calculate the mass fraction of NaOH in the resulting solution, we can use the following formula:

Mass fraction (wt%) = (mass of solute / total mass of solution) × 100%

Given: - Mass of 25% NaOH solution = 43 g - Mass of 40% NaOH solution = 81 g

First, we need to find the total mass of the resulting solution by adding the masses of the two solutions.

Total mass of resulting solution = Mass of 25% NaOH solution + Mass of 40% NaOH solution

Total mass of resulting solution = 43 g + 81 g

Total mass of resulting solution = 124 g

Now, we can calculate the mass fraction of NaOH in the resulting solution using the formula mentioned above.

Mass fraction of NaOH = (mass of NaOH / total mass of solution) × 100%

Let's calculate the mass of NaOH in the resulting solution.

Mass of NaOH in 25% solution = 25% of 43 g

Mass of NaOH in 25% solution = 0.25 × 43 g

Mass of NaOH in 25% solution = 10.75 g

Mass of NaOH in 40% solution = 40% of 81 g

Mass of NaOH in 40% solution = 0.40 × 81 g

Mass of NaOH in 40% solution = 32.4 g

Now, we can find the total mass of NaOH in the resulting solution.

Total mass of NaOH in resulting solution = Mass of NaOH in 25% solution + Mass of NaOH in 40% solution

Total mass of NaOH in resulting solution = 10.75 g + 32.4 g

Total mass of NaOH in resulting solution = 43.15 g

Finally, we can calculate the mass fraction of NaOH in the resulting solution.

Mass fraction of NaOH = (43.15 g / 124 g) × 100%

Mass fraction of NaOH ≈ 34.76%

So, the mass fraction of NaOH in the resulting solution is approximately 34.76%.