1. How many kg of Glaubers salt (Na₂SO₄. 10 H₂O) will be obtained from 250 kg of Na₂SO₄

To determine how many kilograms of Glauber's salt (sodium sulfate decahydrate, Na2SO4·10H2O) can be produced from 250 kg of sodium sulfate (Na2SO4), we need to look at the chemical composition and the molar masses of the compounds involved.

Understanding the Chemical Composition

Glauber's salt is formed when sodium sulfate combines with water. The formula Na2SO4·10H2O indicates that for every mole of sodium sulfate, there are 10 moles of water associated with it. This means that the mass of Glauber's salt includes both the sodium sulfate and the water of crystallization.

Calculating Molar Masses

First, let’s calculate the molar masses:

• Molar mass of Na2SO4:
  • Sodium (Na): 22.99 g/mol × 2 = 45.98 g/mol
  • Sulfur (S): 32.07 g/mol
  • Oxygen (O): 16.00 g/mol × 4 = 64.00 g/mol
  • Total: 45.98 + 32.07 + 64.00 = 142.05 g/mol
• Molar mass of 10H2O:
  • Water (H2O): 18.02 g/mol × 10 = 180.20 g/mol
• Molar mass of Glauber's salt (Na2SO4·10H2O):
  • Total: 142.05 g/mol + 180.20 g/mol = 322.25 g/mol

Using Stoichiometry

Now that we have the molar masses, we can set up a stoichiometric calculation. The relationship between sodium sulfate and Glauber's salt can be expressed as follows:

1 mole of Na2SO4 produces 1 mole of Na2SO4·10H2O.

Calculating the Amount of Glauber's Salt

Next, we need to find out how many moles of Na2SO4 are in 250 kg:

• Convert kilograms to grams: 250 kg = 250,000 g
• Calculate moles of Na2SO4:
  • Moles of Na2SO4 = mass (g) / molar mass (g/mol) = 250,000 g / 142.05 g/mol ≈ 1,761.57 moles

Since 1 mole of Na2SO4 produces 1 mole of Glauber's salt, we will also have approximately 1,761.57 moles of Glauber's salt.

Final Calculation of Mass

Now, we can convert the moles of Glauber's salt back to grams:

• Mass of Glauber's salt = moles × molar mass = 1,761.57 moles × 322.25 g/mol ≈ 567,000 g
• Convert grams back to kilograms: 567,000 g = 567 kg

Thus, from 250 kg of sodium sulfate, you can obtain approximately 567 kg of Glauber's salt (Na2SO4·10H2O).