Question

в 250 мл воды растворили 67,2 л (н.у.) хлороводорода. вычислите массовую долю хлороводорода в полученном растворе.

Answer 1

m(H2O)=250мл*1г/мл=250г

М(НСІ)=36,5

22,4л----------36,5г

67,2л-----------х

х=67,2*36,5/22,4=109,5г

масса (р-ра)=250+109,5=359,5г

мас. доля=109,5/359,5=0,3 или 30%

Answer 2

Calculation of the Mass Fraction of Hydrochloric Acid in the Solution

To calculate the mass fraction of hydrochloric acid (HCl) in the given solution, we need to know the mass of HCl and the total mass of the solution.

According to the information provided, 67.2 liters of hydrochloric acid gas at standard temperature and pressure (n.u.) were dissolved in 250 ml of water.

To calculate the mass of HCl, we need to convert the volume of HCl gas to its mass using its molar mass. The molar mass of HCl is approximately 36.46 g/mol

To convert the volume of HCl gas to its mass, we can use the ideal gas law equation:

PV = nRT

Where: - P is the pressure of the gas (at standard temperature and pressure, it is 1 atm) - V is the volume of the gas (67.2 liters) - n is the number of moles of the gas (which we want to find) - R is the ideal gas constant (0.0821 L·atm/(mol·K)) - T is the temperature in Kelvin (which is assumed to be at standard temperature, 273.15 K)

Rearranging the equation to solve for n:

n = PV / RT

Substituting the values:

n = (1 atm) * (67.2 L) / (0.0821 L·atm/(mol·K) * 273.15 K)

Calculating n:

n ≈ 2.51 mol

Now, we can calculate the mass of HCl:

mass of HCl = n * molar mass of HCl

mass of HCl = 2.51 mol * 36.46 g/mol

Calculating the mass of HCl:

mass of HCl ≈ 91.5696 g

Next, we need to calculate the total mass of the solution. The total mass of the solution is the sum of the mass of water and the mass of HCl:

total mass of solution = mass of water + mass of HCl

Since the volume of water is given as 250 ml, we can assume its density is approximately 1 g/ml. Therefore, the mass of water is 250 g.

total mass of solution = 250 g + 91.5696 g

Calculating the total mass of the solution:

total mass of solution ≈ 341.5696 g

Finally, we can calculate the mass fraction of HCl in the solution:

mass fraction of HCl = (mass of HCl / total mass of solution) * 100%

mass fraction of HCl = (91.5696 g / 341.5696 g) * 100%

Calculating the mass fraction of HCl:

mass fraction of HCl ≈ 26.82%

Therefore, the mass fraction of hydrochloric acid in the obtained solution is approximately 26.82%.