What is the percent by volume of ethanol that contains 35 ml of solute dissolved in 115 ml of water

11.What is the percent by volume of ethanol in a solution that contains35 mL of ethanol dissolved in 115 mL of water?12.If you have 100.0 mL of a 30.0% aqueous solution of ethanol, whatvolumes of ethanol and water are in the solution?13.What is the percent by volume of isopropyl alcohol in a solution thatcontains 24 mL of isopropyl alcohol in 1.1 L of water?Percent by volume usually describes solutions in which both solute and sol-vent are liquids. The percent by volume is the ratio of the volume of the soluteto the volume of the solution expressed as a percent. The volume of the solu-tion is the sum of the volumes of the solute and the solvent. Calculations aresimilar to those involving percent by mass.Percent by volume100Rubbing alcohol is an aqueous solution of liquid isopropyl alcohol. Thelabel on a typical container, such as the one shown inFigure 15-12,usuallystates that the rubbing alcohol is 70% isopropyl alcohol. This value is a per-cent by volume. It tells you that 70 volumes of isopropyl alcohol are dissolvedin every 100 volumes of solution. Because a solution’s volume is the sum ofthe volumes of solute and solvent, there must be 30 volumes of water (sol-vent) in every 100 volumes of the rubbing alcohol.volume of solutevolume of solutionMolarityAs you have learned, percent by volume and percent by mass are only twoof the commonly used ways to quantitatively describe the concentrations ofliquid solutions. One of the most common units of solution concentration ismolarity.Molarity(M) is the number of moles of solute dissolved per literof solution. Molarity also is known as molar concentration. The unitMis readas molar. A liter of solution containing one mole of solute is a 1Msolution,which is read as a one molar solution. A liter of solution containing 0.1 moleof solute is a 0.1Msolution.To calculate a solution’s molarity, you must know the volume of the solu-tion and the amount of dissolved solute.Molarity (M)lmiteorlsesofosfosloultuiotenFor example, suppose you need to calculate the molarity of 100.0 mL of anaqueous solution containing 0.085 mole of dissolved potassium chloride(KCl). You would first convert the volume of the solution from milliliters toliters using the conversion factor 1 L1000 mL.(100 mL)10010LmL0.1000 LThen, to determine the molarity, you would divide the number of moles ofsolute by the solution volume in liters.0.01.000805LmosollKutCioln0.85Lmol0.85MFor more practice withpercent by volumeproblems, go toSupplemental PracticeProblemsin Appendix A.Practice!Figure 15-12The composition of this isopropylalcohol is given in percent by vol-ume, which is often expressed as% (v/v). What does each v in theexpression 70% (v/v) refer to?

15.2Solution Concentration465EXAMPLEPROBLEM15-3Calculating MolarityA 100.5-mL intravenous (IV) solution contains 5.10 g of glucose(C6H12O6). What is the molarity of this solution? The molar mass ofglucose is 180.16 g/mol.