42) How many grams of solution are present if a solute is dissolved in 630 g of water and the concentration is 12.7% by mass? A) 55.0 B) 0.00722 C) 72.2 D) 20.2 E) 1.39 Answer: C

To solve this problem, we need to find the mass of the solute dissolved in the solution.<br /><br />Given information:<br />- The concentration of the solution is 12.7% by mass.<br />- The mass of water is 63.0 g.<br /><br />The formula to calculate the mass of the solute is:<br /><br />Mass of solute = (Concentration by mass × Total mass of solution) / 100<br /><br />Substituting the given values:<br /><br />Mass of solute = (12.7 × (63.0 + x)) / 100<br /><br />Where x is the mass of the solute.<br /><br />Solving for x:<br /><br />12.7 × (63.0 + x) = 100x<br />783.1 + 12.7x = 100x<br />783.1 = 87.3x<br />x = 783.1 / 87.3<br />x ≈ 8.96 g<br /><br />Therefore, the mass of the solute dissolved in the solution is approximately 8.96 g.<br /><br />The correct answer is C) 72.2.