Question

Use the definition of molarity to calculate the concentration of 12.34 g of CaSO4 completely dissolved in water, with a solution volume of 250.0 mL as measured using a volumetric flask. The molar mass of CaSO4 is 136.13 g/mol. Answer with 4 significant digits and include an appropriate unit.

Answer 1

[CaSO₄] = 36.26×10⁻² mol/L

Step-by-step explanation:

Molarity (M) → mol/L → moles of solute in 1L of solution

Let's convert the volume from mL to L

250 mL . 1L/1000 mL = 0.250L

We need to determine the moles of solute. (mass / molar mass)

12.34 g / 136.13 g/mol = 0.0906 mol

M → 0.0906 mol / 0.250L = 36.26×10⁻² mol/L