Home
Class 12
CHEMISTRY
Standard enthaply of vaporisation Delta(...

Standard enthaply of vaporisation `Delta_(vap)H^(theta)` for water at `100^(@)C` is `40.66 kJ mol^(-1)`. The internal energy of vapourisation of water at `100^(@)C` (in `kJ mol^(-1)`) is :

A

`+ 40.66`

B

`+ 37.56`

C

`- 43.76`

D

`+ 43.76`

Text Solution

Verified by Experts

The correct Answer is:
B
`Delta H = Delta U + Delta n_(g) RT`
`H_(2)O(l) rarr H_(2)O(g)`
`Delta n_(g) = 1, Delta H = 40.66 xx 10^(3) Jmol^(-1)`,
T = 373K
`40660 = Delta U + 1 xx 8.314 xx 373`
`40660 = Delta U + 3101.12`
`Delta U = 40660 - 3101.12`
`= 37.558 Jmol^(-1)`
`= 37. 56 kJmol^(-1)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Multiple Choice Questions (Level-III)|10 Videos

  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Recent Examination Question|15 Videos

  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Recent Examination Question|15 Videos

  • THE SOLID STATE

    MODERN PUBLICATION|Exercise RECENT EXAMINATION QUESTIONS|11 Videos

  • UNIT TEST - 3

    MODERN PUBLICATION|Exercise MULTIPLE CHOICE QUESTIONS|59 Videos

Similar Questions

Explore conceptually related problems

The enthalpy of vaporisation of a compound AB a its boiling point (127^(@)C) is 6.4 kJ mol^(-1) . Its entropy of vapourisation is :

If molar heat of vaporization is 9cdot71 k cal mol^(-1) the entropy of evaporation of water at 100^@ C is

Knowledge Check

  • Standard enthalpy of evaporation Delta_(“vap”)H^@ for water at 100^@C is 40 cdot 66 k J mol^(-1) . The internal energy of vaporization of water at 100^@C (in k J mol^(-1) ) is:

    A
    `+37 cdot 56`
    B
    `-43 cdot 76`
    C
    `+43 cdot 76`
    D
    `+ 40 cdot 66`

  • Delta H (vap) for water is 40.7 kJ mol^(-1) . The entropy of vaporisation of water is :

    A
    `- 40.7 kJ mol^(-1) K^(-1)`
    B
    `407 J mol^(-1) K^(-1)`
    C
    `109 J mol^(-1) K^(-1)`
    D
    `722 J mol^(-1)`

  • The enthalpy of vaporisation of water is 186.5 kJ mol^(-1) . The entropy of its vaporisation will be :

    A
    `2.0 JK^(-1)`
    B
    `200 JK^(-1)`
    C
    `0.5 JK^(-1)`
    D
    `1.5 JK^(-1)`

    • Similar Questions

    Explore conceptually related problems

    If the enthalpy of vaporisation of water is 186cdot5 J mol^(-1) the entropy of its vaporisation will be

    If Delta H for a reaction is 100 kJ// mol^(-1) , the minimum value for the energy of activation will be

    The enthalpy of vaporisation for water is 41.2 kJ mol^(-1), DeltaH for the reaction 2H_2O(g) to 2H_2O(l) is :

    The enthalpy of vaporisation of a substance is 8400 J mol^(-1) and its boiling point is -173^(@)C . The entropy change for vaporisation is :

    The standard enthalpy of formation of NH_(3) is - 46.0 kJ mol^(-1) . If the enthalpy of formation of H_(2) from its atoms is - 436 kJ mol^(-1) and that of N_(2) is - 712 kJ mol^(-1) , the average bond enthalpy of N - H bond is NH_(3) is

    Home
    Profile