The solubility‐product constant for BaSO₄ at 25 °C is Ksp=1.1×10−10. An experiment measures the molar solubility of BaSO₄ in a 0.0020 M Na₂SO₄ solution to be 4.5×10−8 M.
(a) Calculate the theoretical percent decrease in BaSO₄ solubility when the salt is dissolved in 0.0020 M Na₂SO₄ instead of pure water.
(b) Using the experimental solubility value, determine the percent error relative to the theoretical solubility in the common‐ion solution. Express both percentages to two significant figures.