MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12th pass
        
The molar volume of liquid benzene increases by a factor of 2750 as it vaporizes at 20 C. At 27 C when a non volatile solute is dissolved in 54.6 cm3 of benzene vapour pressure of this solution is found to be 98.88mmHg. Calculate the freezing point of the solution
 
Given Enthalpy of vapourisation of benzene = 394.57J/g
Enthalpy of fusion of benzene(l) = 10.06KJ/mol
Molal depression constant for benzene= 5.0 K Kg/ Mol
one year ago

Answers : (1)

Arun
23008 Points
							
Please find the answer to your question
 
(i)Volume = No. of moles * molar mass/density
(ii) PV = nRT or P = nRT/V
Volume of 1 mole of liq. Benzene = 78/0.877
Volume of 1 mole of toluene. 92/0.867
In vapour phase,
At 20oC, for 1 mole of benzene,
Volume = 1 **78 *2750/0.877 = 244583.80 mL
= 244.58 L
Similarly for 1 mole of toluene,
Volume = 1 *92/0.867 * 7720
= 819192.61 mL = 819.199 L
As we know that, PV = nrt
For benzene, PoB = nRT/V = 1 *0.0821 *293/244.58 atm
= 0.098 atm
For toluene, PoT = nRT/V = 1 *0.0825 *293/819.19 atm = 0.029 atm
P = PoB.XB + PoT.XT
XB + XT = 1
 XT= 1 - XB
P = PoB.XB + PoT (1 – XB)
Total vapour pressure = 46 torr = 46/760 = 0.060 atm
Thus, 0.060 = 0.098 XB + 0.029 (1 - XB)
⇒ 0.060 = 0.098 XB + 0.029 – 0.029 XB
⇒ 0.031 = 0.069 XB
∴ XB = 0.031/0.069 = 0.45 (in liquid phase)
XB + XT = 1
XT = 1 – 0.45 = 0.55 (in liquid phase)
Also, PB = PoB.XB = PX’B
So, 0.098 * 0.045 = 0.060 * XB
XB = 0.098 * 0.45/0.060 = 0.735 (in gas phase)
one year ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 141 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details