--%>
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 : Short note on the function of

    Write down a short note on the function of mitochondria?

    		•
  • Q : BASIC CHARACTER OF AMINES IN GAS PHASE,

    IN GAS PHASE, BASICITIES OF THE AMINES IS JUST OPPOSITE TO BASICITY OF AMINES IN AQEUOUS PHASE .. EXPLAIN

    		•
  • Q : Procedure for separating the components

    Briefly describe the procedure for separating the components of the gun-powder?

    		•
  • Q : Amines arrange in order of

    arrange in order of basicity,pyridine,pipyridineand pyorine

    		•
  • Q : Define thermal energy The thermal part

    The thermal part of the internal energy and the enthalpy of an ideal gas can be given a molecular level explanation. All the earlier development of internal energy and enthalpy has been "thermodynamic". We have made no use o

    		•
  • Q : Organic and inorganic chemistry Write

    Write down a short note on the differences between the organic and inorganic chemistry?

    		•
  • Q : Explain equilibrium and molecular

    The equilibrium constant can be treated as a particular type of molecular distribution. Consider the simplest gas-phase reaction, one in which molecules of A are converted to molecules of B. the reaction, described by the equation

    Q : Problem associated to vapour pressure

    Provide solution of this question. 60 gm of Urea (Mol. wt 60) was dissolved in 9.9 moles, of water. If the vapour pressure of pure water is P0 , the vapour pressure of solution is:(a) 0.10P0 (b) 1.10P0 (c) 0.90P0 (d) 0.99P0

    		•
  • Q : Solubility product On passing H 2 S gas

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

    		•
  • Q : How to calculate solutions molar

    The contribution of an electrolyte, or an ion electrolyte, is reported as the molar of a conductance. The definition of the molar conductance is based on the following conductivity cell in which the electrodes are 1 m apart and of sufficient area that th

    		•