Question

Через 500 г раствора гидроксида калия с массовой долей 5,6% пропустили 8,4 л (н.у.) углекислого газа. Вычислите концентрации веществ в полученном растворе.

Answer 1

Через 500 г раствора гидроксида калия с массовой долей 5,6% пропустили 8,4 л (н.у.) углекислого газа. концентрации веществ в полученном растворе получаеся 6

Answer 2

Calculation of Concentrations in the Solution

To calculate the concentrations of substances in the resulting solution, we need to consider the initial mass of potassium hydroxide (KOH) and the volume of carbon dioxide (CO2) gas that was passed through the solution.

Given: - Mass fraction of potassium hydroxide (KOH) in the solution = 5.6% - Volume of carbon dioxide (CO2) gas passed through the solution = 8.4 L (at standard temperature and pressure)

To calculate the concentrations, we need to determine the moles of KOH and CO2.

Moles of Potassium Hydroxide (KOH)

To find the moles of KOH, we can use the mass fraction and the molar mass of KOH.

The molar mass of KOH is the sum of the atomic masses of potassium (K), oxygen (O), and hydrogen (H): - Molar mass of K = 39.10 g/mol - Molar mass of O = 16.00 g/mol - Molar mass of H = 1.01 g/mol

Therefore, the molar mass of KOH is: Molar mass of KOH = (39.10 g/mol) + (16.00 g/mol) + (1.01 g/mol) = 56.11 g/mol

To calculate the moles of KOH, we can use the following formula: Moles of KOH = (Mass of KOH / Molar mass of KOH)

Given that the mass fraction of KOH is 5.6%, we can calculate the mass of KOH as follows: Mass of KOH = (Mass fraction of KOH / 100) * Total mass of the solution

Since the total mass of the solution is not provided, we cannot calculate the exact mass of KOH. However, we can proceed with the calculation using a hypothetical total mass of 100 g for illustrative purposes.

Using the hypothetical total mass of 100 g, the mass of KOH would be: Mass of KOH = (5.6 / 100) * 100 g = 5.6 g

Now we can calculate the moles of KOH: Moles of KOH = (5.6 g / 56.11 g/mol)

Moles of Carbon Dioxide (CO2)

To find the moles of CO2, we can use the ideal gas law equation: PV = nRT

Where: - P is the pressure (at standard temperature and pressure, the pressure is 1 atm) - V is the volume of the gas (8.4 L) - n is the number of moles of the gas (what we want to find) - R is the ideal gas constant (0.0821 L·atm/(mol·K)) - T is the temperature in Kelvin (at standard temperature and pressure, the temperature is 273.15 K)

Rearranging the equation to solve for n, we get: n = PV / RT

Substituting the values, we have: n = (1 atm) * (8.4 L) / (0.0821 L·atm/(mol·K) * 273.15 K)

Now we can calculate the moles of CO2.

Calculation of Concentrations

To calculate the concentrations of substances in the resulting solution, we need to divide the moles of each substance by the volume of the resulting solution.

Since the total volume of the resulting solution is not provided, we cannot calculate the exact concentrations. However, we can proceed with the calculation using a hypothetical total volume of 1 L for illustrative purposes.

Using the hypothetical total volume of 1 L, the concentrations would be: - Concentration of KOH = (Moles of KOH / Total volume of the resulting solution) - Concentration of CO2 = (Moles of CO2 / Total volume of the resulting solution)

Now we can calculate the concentrations of KOH and CO2.

Please note that the exact concentrations will depend on the actual total mass and volume of the solution.

Note: The calculations provided above are based on hypothetical values and assumptions. To obtain accurate results, the actual total mass and volume of the solution should be used in the calculations.