The percent of a solute in a solution is defined as the mas of solute in 100 grams of solution. A 20% solution of sulfuric acid contains 20% pure H2SO4 by mass and 80% pure H2O by mass. In 100 grams of H2SO4 there are 20 grams of sulfuric acid and 80 grams of water. Assume water is the solvent. If 18.0 grams of sodium sulfate are dissolved in 207.0 grams of water, what is the percent concentration of this solution?