A solution was prepared by dissolving 36.0 g of KCl in 225 g of water. A) Calcul

Question

A solution was prepared by dissolving 36.0 g of KCl in 225 g of water.

A) Calculate the mass percent of KCl in the solution. Express your answer with the appropriate units

B) Calculate the mole fraction of the ionic species KCl in the solution. Express the concentration numerically as a mole fraction in decimal form.

C) Calculate the molarity of KCl in the solution if the total volume of the solution is 239 mL. Express your answer with the appropriate units.

D) Calculate the molality of KCl in the solution. Express your answer with the appropriate units.

Explanation / Answer

total mass = 36+225 = 261g

mass percentage of KCl   = mass of KCl*100/total mass

                                            = 36*100/261 = 13.79%

no of moles of KCl   = mass of KCl/gram molar mass of KCl

                                 = 36/74.5 =0.48 moles

no of moles of H2O   = 225/18   = 12.5moles

mole fraction of KCl = no of moles of KCl/ no of moles of KCl + no of moles of water

                                    = 0.48/0.48+12.5   = 0.48/12.98 = 0.037

C. molarity                = no of moles/ volume in L

                                    = 0.48/0.239 = 2M

D. molality                  = no of moles /mass of water in Kg

                                   = 0.48/0.225   = 2.13 m

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.