Question

Какой объем серной кислоты с массовой долей 24% ( плотность расствора 1,17 г/мл) необходим для приготовления 2 л раствора с молярной концентрацией 0.2 моль/л​

Answer 1

Calculating the Volume of Sulfuric Acid Needed

To calculate the volume of sulfuric acid needed to prepare a 2 L solution with a molar concentration of 0.2 mol/L, we can use the formula:

Volume (in liters) = Number of moles / Molarity

Given that the molar concentration is 0.2 mol/L and the volume is 2 L, we can calculate the number of moles of sulfuric acid needed using the formula:

Number of moles = Molarity × Volume

Substituting the given values: Number of moles = 0.2 mol/L × 2 L = 0.4 moles

Now, to find the mass of sulfuric acid needed, we can use its molar mass and the number of moles calculated.

Molar Mass of Sulfuric Acid

The molar mass of sulfuric acid (H2SO4) can be calculated by adding the atomic masses of its constituent elements.

- Hydrogen (H): 1.00794 g/mol - Sulfur (S): 32.065 g/mol - Oxygen (O): 15.999 g/mol

The molar mass of sulfuric acid (H2SO4) = 2(1.00794 g/mol) + 32.065 g/mol + 4(15.999 g/mol)

Calculating the molar mass: Molar mass of H2SO4 = 2.01588 g/mol + 32.065 g/mol + 63.996 g/mol = 98.07988 g/mol

Calculating the Mass of Sulfuric Acid Needed

Using the number of moles calculated earlier (0.4 moles) and the molar mass of sulfuric acid, we can find the mass of sulfuric acid needed.

Mass of sulfuric acid (in grams) = Number of moles × Molar mass

Substituting the given values: Mass of sulfuric acid = 0.4 moles × 98.07988 g/mol = 39.231952 g

Therefore, approximately 39.23 grams of sulfuric acid with a mass fraction of 24% would be needed to prepare a 2 L solution with a molar concentration of 0.2 mol/L.

Answer

Approximately 39.23 grams of sulfuric acid with a mass fraction of 24% would be needed to prepare a 2 L solution with a molar concentration of 0.2 mol/L.