Question

Определить массу раствора серной кислоты( массовая доля H₂SO₄ в котором 30%), который потребуется для полной нейтрализации 200г раствора щёлочи( массовая доля NaOH в этом растворе 20%)!?

Answer 1

M(NaOH) = 200*0.2 = 40г
n(NaOH) = m/M = 40/40 = 1 моль
2NaOH  + H2SO4 = Na2SO4 + H2O
n(H2SO4) = 1*1/2 = 0.5 моль
m(H2SO4) = n*M = 0.5*98 = 49 г
m(раствора H2SO4) = 49/0.3 = 163.3 г 

Answer 2

Calculation of the Mass of Sulfuric Acid Solution

To determine the mass of the sulfuric acid solution needed for the complete neutralization of 200g of the alkaline solution, we need to consider the mass fraction of sulfuric acid (H₂SO₄) in the solution.

Given: - Mass of the alkaline solution = 200g - Mass fraction of sodium hydroxide (NaOH) in the alkaline solution = 20% - Mass fraction of sulfuric acid (H₂SO₄) in the sulfuric acid solution = 30%

To calculate the mass of the sulfuric acid solution, we can follow these steps:

1. Calculate the mass of NaOH in the alkaline solution: - Mass of NaOH = Mass of the alkaline solution * Mass fraction of NaOH - Mass of NaOH = 200g * 0.20 - Mass of NaOH = 40g

2. Determine the stoichiometric ratio between NaOH and H₂SO₄: - From the balanced chemical equation for the neutralization reaction between NaOH and H₂SO₄, we know that the ratio is 1:1. This means that 1 mole of NaOH reacts with 1 mole of H₂SO₄.

3. Calculate the molar mass of NaOH: - The molar mass of NaOH is the sum of the atomic masses of its constituent elements: Na (sodium), O (oxygen), and H (hydrogen). - Molar mass of NaOH = (1 * atomic mass of Na) + (1 * atomic mass of O) + (1 * atomic mass of H) - Molar mass of NaOH = (1 * 22.99 g/mol) + (1 * 16.00 g/mol) + (1 * 1.01 g/mol) - Molar mass of NaOH = 39.99 g/mol

4. Calculate the number of moles of NaOH: - Number of moles of NaOH = Mass of NaOH / Molar mass of NaOH - Number of moles of NaOH = 40g / 39.99 g/mol - Number of moles of NaOH ≈ 1.000 mol

5. Calculate the number of moles of H₂SO₄: - Since the stoichiometric ratio between NaOH and H₂SO₄ is 1:1, the number of moles of H₂SO₄ is also approximately 1.000 mol.

6. Calculate the mass of H₂SO₄ in the sulfuric acid solution: - Mass of H₂SO₄ = Number of moles of H₂SO₄ * Molar mass of H₂SO₄ - Molar mass of H₂SO₄ = (2 * atomic mass of H) + atomic mass of S + (4 * atomic mass of O) - Molar mass of H₂SO₄ = (2 * 1.01 g/mol) + 32.07 g/mol + (4 * 16.00 g/mol) - Molar mass of H₂SO₄ = 98.09 g/mol - Mass of H₂SO₄ = 1.000 mol * 98.09 g/mol - Mass of H₂SO₄ ≈ 98.09 g