Use the following data to determine the freexing pointdepression constant, K f ,

Question

Use the following data to determine the freexing pointdepression constant, Kf, for phenol. freezing point of phenol 42.96oC freexing point of solution 39.74oC volume of phenol 25.00mL density of phenol 1.0576g/mL mass of solute 0.5288g molecular weight of solute 46.0g/mol Use the following data to determine the freexing pointdepression constant, Kf, for phenol. freezing point of phenol 42.96oC freexing point of solution 39.74oC volume of phenol 25.00mL density of phenol 1.0576g/mL mass of solute 0.5288g molecular weight of solute 46.0g/mol

Explanation / Answer

We know that depression in freezing point , T f = Kf *m
Where m = molality = ( mass / Molar mass ) / Mass of solvent inKg We know that density , d = mass / Volume         Mass of phenol , m= d * Volume                                        = 1.0576 g / mL * 25 mL                                        = 26.44 g                                        = 0.02644 Kg Mass of the solute = 46 g / mol    So , m = ( 0.5288 / 46 ) / 0.02644              = 0.4347 Depression in freezing point , T f = freezing point ofphenol - freexing point of solution                                                     = 42.96 - 39.74                                                     = 3.22 oC Plug the values we get 3.22 = Kf * 0.4347                                      Kf = 7.406

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

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