Colligative Properties: Freezing Point Depression Part B Mass of tube and naphth
ID: 712878 • Letter: C
Question
Colligative Properties: Freezing Point Depression Part B Mass of tube and naphthalene- Mass of naphthalene g Mass of tube and naphthalene and para-dichlorobenzeneeda Mass of paradichlorobenzene g Freezing point of naphthalene/para-dichlorobenzene solution (Attach graph.) change in freezing point from that of pure naphthalene Molality of para-dichlorobenzene solution K, for naphthalene Time (sec) Temperature C'C) 30 60 90 120 150 180 210 240 270 300 330 420 450 480 510 540 570 600 Copyright © 2017 Pearson Education, Inc.Explanation / Answer
1. 128.17 g/mol
2. pure naphthalene which has 78 freezing point, normally freezing point (freezing point = 75 ).
3. Molality is moles of solute per Kg of solvent. So your moles of solute are calculated by dividing 2.70 grams by the molar mass of the dichlorobenzene (147 rounded) and the Kg of solvent are calculated by multiplying the volune of benzene by the density so your Molality is 0.01837moles divided by 0.04395kg. which is 0.42 Molal.
4. The Kf for napthalene is 6.80.
5. molar mass of paradichlorobenzene is 146.998 g/mol
6. freezing point is PDB is 53.2°C and for nepthalene is 80.26 °C.