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What is the percentage by mass of a solution with 42.5 g chlorine granules dissolved in water to make 950.0 g of a solution |
| Answer» <html><body><p>The percentage concentration of any solution is most commonly expressed as mass percent:Mass % of any component of the solution =(Mass of the component in the solution / Total mass of the solution) x 100Other methods are:Volume percentage:Volume % of a component =(Volume of the component/Total volume of the solution) x 100Mass by volume percentage:It is the mass of solute dissolved in 100 mL of the solution.i.e. Mass by Volume percentage =(Mass of solute in grams/Volume of solution in mL) x 100Here's a point to be kept in mind :Whenever we say mass or volume of the solution, you <a href="https://interviewquestions.tuteehub.com/tag/need-25476" style="font-weight:bold;" target="_blank" title="Click to know more about NEED">NEED</a> to add the respective <a href="https://interviewquestions.tuteehub.com/tag/masses-1088822" style="font-weight:bold;" target="_blank" title="Click to know more about MASSES">MASSES</a> and volumes of ALL the components of the solution. Do NOT commit the error of <a href="https://interviewquestions.tuteehub.com/tag/taking-1238585" style="font-weight:bold;" target="_blank" title="Click to know more about TAKING">TAKING</a> the mass or volume of only the solute or solvent in the denominators of the above expressions.The concentration of a solution is most of the time expressed as the number of moles of solute present in 1 Liter of the solution (also called molarity )(There are also other ways to express concentration. Please <a href="https://interviewquestions.tuteehub.com/tag/follow-994211" style="font-weight:bold;" target="_blank" title="Click to know more about FOLLOW">FOLLOW</a> this link. )EXAMPLE:(a) If 25 moles of NaCl are present in 100 L of a solution wherein <a href="https://interviewquestions.tuteehub.com/tag/h2o-479118" style="font-weight:bold;" target="_blank" title="Click to know more about H2O">H2O</a> is the solvent, then the concentration of the solution is 25100=0.25mol⋅L−1 .(b) What is the molarity of a solution prepared by dissolving 15.0 g of sodium hydroxide in enough water to make a total of 225 mL of solution?SolutionCalculate the number of moles of solute present.Moles of NaOH = 15.0 g NaOH × 1mol NaOH40.00g NaOH = 0.375 mol NaOHCalculate the number of litres of solution present.Volume = 225 mL × 1L1000mL = 0.225 L solnDivide the number of moles of solute by the number of litres of solution.Molarity = 0.375mol0.225L = 1.67 mol/L</p></body></html> | |