Question

к раствору массой 245 г и массовой долей 41% добавили 50 мл воду . Найти массовую долю в полученом растворе​

Answer 1

В растворе массовая доля показывает содержание самого вещества. После добавления воды процентное содержание вещества в растворе теоретически уменьшится. Нам не даны сами вещества. Поэтому отталкиваемся от того, что есть.

245 г - 100%  (раствор вместе с водой)

х г - 41% (самого вещества в растворе)

х=245*41/100=100,45 г= m(в-ва)

m(H2O)=V/P=50мл/ 1г/мл=50г

m2(раствора)=100,45г+50г=150,45г (масса раствора после прилития воды)

w= m (в-ва) / m2(р-ра) * 100 =  100,45г/150,45г*100%=66,77%

Answer 2

Calculating the Mass Fraction of the Solution

To find the mass fraction of the resulting solution after adding 50 ml of water to a solution with a mass of 245 g and a mass fraction of 41%, we can use the following formula:

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

Let's calculate the mass fraction using the given information.

The mass of the solute is 245 g, and the mass fraction of the solute is 41%. We need to find the mass of the solvent (water) added to the solution.

Calculation

Using the given information, we can calculate the mass of the solvent added to the solution:

Mass of solute = 245 g Mass fraction of solute = 41% Volume of solvent added = 50 ml

Now, let's calculate the mass fraction of the resulting solution.

Step 1: Calculate the mass of the solute: - Mass of solute = 245 g Step 2: Calculate the mass of the solvent (water) added: - Volume of solvent added = 50 ml

Step 3: Calculate the total mass of the resulting solution: - Total mass of solution = Mass of solute + Mass of solvent

Step 4: Calculate the mass fraction of the resulting solution: - Mass Fraction (w/w%) = (mass of solute / total mass of solution) × 100

Let's perform the calculations to find the mass fraction of the resulting solution.