Question

4.550 g of Na2SO4 are added to 0.350 L of water. To this solution, 0.085 L of water were added. What is the new concentration of the solution?

Answer 1

0.0736 M or 10.4 g/L

Step-by-step explanation:

First we convert 4.550 g of Na₂SO₄ into moles, using the molar mass of Na₂SO₄:

• 4.550 g ÷ 142.04 g/mol = 0.0320 mol

Then we calculate the final volume of the solution:

• Final Volume = 0.350 L + 0.085 L

• Final Volume = 0.435 L

Now we can proceed to calculate the concentration -in molarity- of the solution:

• Molarity = moles / liters

• 0.0320 mol / 0.435 L = 0.0736 M

In g/L the concentration would be:

• 4.550 g / 0.435 L = 10.4 g/L