Question

Из 600 г 20% раствора соли выпарили 200 г воды. Какова массовая доля полученого раствора

Answer 1

Дано:
m₁(р-ра)=600г.
ω%=20%
m(H₂O)=100
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ω%₂(р-ра соли)

1. Определим массу соли в растворе:
m(соли)=ω%×m₁(р-ра)÷100%=20%х600г.÷100%=120г.
2. Определим массу раствора после выпаривания 100г. воды:
m₂(р-ра)=m₁(р-ра)-m(H₂O)=600г.-100г=500г.
3. Определим массовую долю нового раствора соли:
ω₂%=m(соли)÷m₂(р-ра)×100%=120г÷500г.×100%=24%
4. Ответ массовая доля нового раствора соли 24%

Answer 2

Calculation of Mass Fraction of the Resulting Solution

To calculate the mass fraction of the resulting solution, we can use the following steps:

1. Calculate the Mass of the Salt in the Original Solution: - The original solution is a 20% salt solution with a total mass of 600 g. - Therefore, the mass of the salt in the original solution is 20% of 600 g, which is 0.20 * 600 g = 120 g.

2. Calculate the Mass of the Salt in the Resulting Solution: - When 200 g of water is evaporated from the original solution, the mass of the salt remains the same at 120 g.

3. Calculate the Total Mass of the Resulting Solution: - The total mass of the resulting solution is the sum of the remaining salt and the water, which is 120 g (salt) + 400 g (water) = 520 g.

4. Calculate the Mass Fraction of the Resulting Solution: - The mass fraction of the resulting solution is the mass of the salt in the resulting solution divided by the total mass of the resulting solution, which is 120 g / 520 g = 0.2308 or 23.08%.

Therefore, the mass fraction of the resulting solution is 23.08%.