--%>
Assignment Help - homework help

What is Elevation in boiling point?

The boiling of a liquid may be defused by the temperature at which its vapour pressure which is equal to atmospheric pressure. The effect of addition in a non-volatile solute on the boiling point shown and its solution containing non-volatile solute with temperature are represented by the curves AB and CD respectively. It is evident by the curves temperature the vapour pressure of solutions is lower than that of the pure solvent and thus, the vapour pressure.

Curve for solution runs below that of the pure solvent. At temperature T0, the vapour pressure of the pure solvent becomes equal to the atmospheric pressure. Thus, the atmospheric pressure and therefore, it is necessary to heat the solution to a higher temperature sayT1 in the atmospheric pressure. Thus, it is clear that the solution in higher temperature than the pure solvent. Evidence T1 - T0 (or Δ Tb)is the elevation in boiling point vapour pressure (Δp), the elevation in the boiling point is also proportional to the solute concentration. Thus,

ΔTb ∝ Δp

According to Raoult's law, Δp ∝ xB

∴ ΔTb ∝ xB

1444_elevation in boiling point.png 

1084_elevation in boiling point1.png 

1730_elevation in boiling point2.png 

1333_elevation in boiling point3.png 

If WA is the mass of solvent in kg, then  1283_elevation in boiling point4.png is equal to molality (m) of the solution

ΔTb = kMA m

Here, k and MA are constants and hence their product, i.e. kMA is replaced by another constant K2.

ΔTb = Kb m, where Kb is called boiling point-elevation constant or molal elevation constant or molal ebullioscopic constant.

As elevation in boiling point depends upon the relative number of moles of solute and solvent but does not depend upon the nature of solute, so it is a colligative property.

   Related Questions in Chemistry

  • Q : Calculating molarity of a solution

    Select the right answer of the question .The molarity of a 0.2 N N2Co3 solution will be: (a) 0.05 M (b) 0.2 M (c) 0.1 M (d)0.4 M

    		•
  • Q : Explosions produce carbon dioxide

    Illustrate all the explosions produce carbon dioxide?

    		•
  • Q : Explain Phase Rule The relation between

    The relation between the number of phases, components and the degrees of freedom is known as the phase rule. One constituent systems: the identification of an area on a P-versus-T with one phase of a component system illustrates the two degrees of freedom that

    		•
  • Q : Polyhalogen compounds we need 10

    we need 10 examples for the polyhalogen compounds....please help me....need it urgently...

    		•
  • Q : Thermodynamics 1 Lab Report I already

    I already did Materials and Methods section. I uploaded it with the instructions. Also, make sure to see Concept Questions and Thinking Ahead in the instructions that I uploaded. deadline is tomorow at 8 am here is the link to download all instructions because I couldn't attach all of t

    		•
  • Q : Quastion of finding vapour pressure

    Vapour pressure of CCl425Degree C at is 143mm of Hg0.5gm of a non-volatile solute (mol. wt. = 65) is dissolved in 100ml CCl4 .Find the vapour pressure of the solution (Density of CCl4 = = 1.58g /cm2): (a)141.43mm (b)

    		•
  • Q : Calculate molarity of a solution

    Provide solution of this question. Molarity of a solution prepared by dissolving 75.5 g of pure KOH in 540 ml solution is: (a) 3.05 M (b) 1.35 M (c) 2.50 M (d) 4.50 M

    		•
  • Q : Changes in matter law of chemical

    changes in matter law of chemical combination

    		•
  • Q : What is Spectroscopy? This is a very

    This is a very important aspect of Physical Chemistry in which knowledge of the size, shape, rigidity and electronic structure of molecules deduced from the experimental methods treated here goes hand in hand with the theoretical approaches of chemical reactions. Spec

    		•
  • Q : Oxoacids of halogens Why oxidising

    Why oxidising character of oxoacids of halogens decreases as oxidation number increases?

    		•