Question

Оксид азота 4 объемом 2,24л(н.у) растворили в 94,6г воды в присутствии кислорода. Определите массовую долю(в%) кислоты в полученном растворе.

Answer 1

4NO2 + O2 + 2H2O = 4HNO3

n(NO2) = 2,24/22,4 = 0,1 моль
m(NO2) = 0,1*46 = 4,6 г
n(NO2)/n(O2) = 4/1
n(O2) = n(NO2)/4 = 0,1/4 = 0,025 моль
m(O2) = 0,025*32 = 0,8 г 
n(NO2)/n(HNO3) = 4/4 = 1/1
n(HNO3) = n(NO2) = 0,1 моль
m(HNO3) = 0,1*63 = 6,3 г
w(X) = m(X)/m
m = 94,6 + 4,6 + 0,8 = 100 г
w(HNO3) = 6,3/100 = 0,063 

 

Ответ: 6,3%

Answer 2

Calculating the Mass Fraction of Acid in the Solution

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

1. Determine the Molar Mass of Nitric Acid (HNO3) - The molar mass of nitric acid (HNO3) is 63.01 g/mol.

2. Calculate the Moles of Nitric Acid - We can use the ideal gas law to calculate the moles of nitric acid: - Volume of gas (V) = 2.24 L - Temperature (T) = standard temperature (0°C or 273.15 K) - Pressure (P) = standard pressure (1 atm or 101.3 kPa) - Using the ideal gas law equation: PV = nRT, where R is the ideal gas constant (0.0821 L·atm/(K·mol)), we can calculate the moles of nitric acid.

3. Calculate the Mass of Nitric Acid - Once we have the moles of nitric acid, we can calculate the mass using the molar mass.

4. Determine the Mass Fraction of Nitric Acid - Finally, we can determine the mass fraction of nitric acid in the solution by dividing the mass of nitric acid by the total mass of the solution (mass of nitric acid + mass of water).

Let's proceed with the calculations.