Question

The normal boiling point of benzene C6H6 is 80.100 °C and its Kbp value is 2.53 °C/m. In a laboratory experiment, students synthesized a new compound and found that when 13.70 grams of the compound were dissolved in 209.0 grams of benzene, the solution began to boil at 80.568 °C. The compound was also found to be nonvolatile and a nonelectrolyte. What is the molecular weight they determined for this compound? D g/mol

Answer 1

These numericale are basedob Elevation in boiling point ( $\bigtriangleup$ Tb ) it is difference betwwen boiling point of soution and boiling point of solvent.

$\bigtriangleup$ Tb become directly proportional to the molality of solution.

$\bigtriangleup$ Tb   $\alpha$ Molality of solution

$\bigtriangleup$ Tb   = Kbp Molality of solution, Where   Kbp = molal elevation constant

l B.l of Benzene (BPsalent) = 801100°c Bis of solution (BB calution) = 80 568°c. Elenction in Bailing paint AT = BP salution Bl Salent = 80.568-B0100 DTL = 0.46 8 C ut of salute (wa) = 13170 gromo ut of salment (WA) = 209.0 gron Kbp = 2,53 °C/M. Salute is non electrolyte. 1821 Elenction in Bailing paint (AT) is the diffence Between Bp of salution and Barling part of saluent ATG Become directly proportion to malality of salectia AT a malality STb - Kbp x malality - WR 1000 Wer ut. of salute Mo WA WA aut. of saleent MB - Malule mace of Calute 0.468 = 2.53 x 13.70 1000 MB 209,0 2.53 x 13.70X1000 MB = 34661 971812 O 0.468 x 209.0 0.468 X 209.0 - 354.36 grom Malcular weight of the compend is 354.36 Sram 2 Curson Bailing paint of salment (BP salleant) = 80noo °c Berlin paint of salution (BPealutor) = 80.591 C eleuction in Bop (ots) - Bi salution - Bi saluent = 80. 59 - 80.100 2 01491 ut of salute (Wim) = 11.30 goon ut of salvent (WA) = 20210 goom Kbp = 2.53 oc/m Malculle weiset of calente (Ma) = 2 Formule Kept cos x 1000 WA Salute is Non-electrolyte 11=2] 0.491 = 2:53 * 11.30 x 1000 Me 202.0 Me - 2.53 x 11:30 x 1000 0.491 x 2020 28589 288. 24 99.182 gran The malule neight of Salute = 288.24 gran Scanned with CamScanner