--%>
Assignment Help - homework help

Molar mass of solute

The boiling point of benzene is 353.23 K. If 1.80 gm of a non-volatile solute was dissolved in 90 gm of benzene, the boiling point is increased to 354.11 K. Then the molar mass of the solute is:

(a) 5.8g mol-1  (b) 0.58g mol-1  (c) 58g mol-1  (d) 0.88 g mol-1         

Answer: (c) The elevation (ΔTb) in the boiling point
= 354.11 K - 353.23 K = 0.88 K
         
Substituting these values in expression
Msolute    = (Kb x 1000 x w)/ΔTb x W     
Where, w = weight of solute, W = weight of solvent
         
Msolute = (2.53 x 1.8 x 1000)/(0.88 x 90)  = 58 gm mol-1
Hence, molar mass of the solute = 58 gm mol-1

   Related Questions in Chemistry

  • Q : Composition of the vapour Choose the

    Choose the right answer from following. An ideal solution was obtained by mixing methanol and ethanol. If the partial vapour pressure of methanol and ethanol are 2.619KPa and 4.556KPa respectively, the composition of the vapour (in terms of mole fraction) will be: (

    		•
  • Q : Solution and colligative properties

    what is molarity of a solution of hcl which contains 49% by weight of solute and whose specific gravity is 1.41

    		•
  • Q : Precipitation problem On passing H 2 S 

    On passing H2S  gas through a solution of Cu+ and Zn+2 ions, CuS is precipitated first because: (i) Solubility product of CuS is equal to the ionic product of ZnS (ii) Solubility product of CuS is equal to the solubility product o

    		•
  • Q : How molecule-molecule collisions takes

    An extension of the kinetic molecular theory of gases recognizes that molecules have an appreciable size and deals with molecule-molecule collisions. We begin studies of elementary reactions by investigating the collisions b

    		•
  • Q : Molecular substances what are the most

    what are the most important inorganic molecular substances for living beings?

    		•
  • Q : Explain various chemicals associated

    During processing of food, several chemicals are added to it to augment its shelf life and to make it more attractive as well. Main types of food addi

    		•
  • Q : Advantages of doing your own chemistry

    What are the advantages of doing your own chemistry assignments? State your comment?

    		•
  • Q : Finding Normality Can someone please

    Can someone please help me in getting through this problem. Concentrated H2SO4 has a density of 1.98 gm/ml and is 98% H2SO4 by weight. The normality is: (a) 2 N  (b) 19.8 N  (c) 39.6 N  (d) 98

    		•
  • Q : Question associated to vapour pressure

    Choose the right answer from following. The vapour pressure lowering caused by the addition of 100 g of sucrose(molecular mass = 342) to 1000 g of water if the vapour pressure of pure water at 25degree C is 23.8 mm Hg: (a)1.25 mm Hg (b) 0.125 mm Hg (c) 1.15 mm H

    		•
  • Q : Vapour pressure of a liquid Help me to

    Help me to go through this problem. The vapour pressure of a liquid depends on: (a) Temperature but not on volume (b) Volume but not on temperature (c) Temperature and volume (d) Neither on temperature nor on volume

    		•