Home
Class 11
CHEMISTRY
An endotthermic reaction is non-spontane...

An endotthermic reaction is non-spontaneous at freezing point of water and becomes feasible at its boiling point, then:

A

`DeltaH=-ve, DeltaS=+ve`

B

Both `DeltaH` and `DeltaS` are `+ve`

C

Both `DeltaH` and `DeltaS` are `-ve`

D

`DeltaH=+ve,DeltaS=-ve`

Text Solution

Verified by Experts

The correct Answer is:
b
`DeltaG=Delta H-TDeltaS`
At low `T,DeltaH` and `DeltaS` are + ve but `DeltaG` is also +ve. At high temperature `TDeltaSgtDeltaH` and `DeltaG=-ve`.
Promotional Banner

Topper's Solved these Questions

  • THERMOCHEMISTRY

    P BAHADUR|Exercise Exercise 9 Advance numerical problems|31 Videos

Similar Questions

Explore conceptually related problems

Free enegry , G = H - TS , is state function that indicates whther a reaction is spontaneous or non-spontaneous. If you think of TS as the part of the system's enegry that is disordered already, then (H -TS) is the part of the system's energy that is still ordered and therefore free to cause spontaneous change by becoming disordered. Also, DeltaG = DeltaH - T DeltaS From the second law of thermodynamics, a reaction is spontaneous if Delta_("total")S is positive, non-spontaneous if Delta_("total")S is negative, and at equilibrium if Delta_('total")S is zero. Since, -T DeltaS = DeltaG and since DeltaG and DeltaS have opposite sings, we can restate the thermodynamic criterion for the spontaneity of a reaction carried out a constant temperature and pressure. IF DeltaG lt 0 , the reaction is spontaneous. If DeltaG gt 0 , the reaction is non-spontaneous. If DeltaG = 0 , the reaction is at equilibrium. Read the above paragraph carefully and answer the following questions based on the above comprehension. If an endothermic reaction is non-spontaneous at freezing point of water and becomes feasible at its boiling point, then

If an endothermic reaction is non - spontaneous at freezing of water and becomes feasible at its boiling point, then

A reaction is non-spontaneous when:

Boiling point of water

The following reaction is non-spontaneous

P BAHADUR-THERMODYNAMICS-Exercise
  1. The reversible expansion of an ideal gas under adiabatic and isotherma...

    Text Solution

    |

  2. For an ideal gas, consider only P-V work in going from an initial stat...

    Text Solution

    |

  3. An endotthermic reaction is non-spontaneous at freezing point of water...

    Text Solution

    |

  4. A heat engine absorbs heat Q(1) at temperature T(1) and Q(2) at temper...

    Text Solution

    |

  5. In an irreversible process taking place at constant T and P and in whi...

    Text Solution

    |

  6. The internal energy change when a system goes fromk state A to B is 40...

    Text Solution

    |

  7. The correct relationship between free energy change in a reaction and ...

    Text Solution

    |

  8. An ideal gas expands from 1xx10^(-3)m^(3) to 1xx10^(-2)m^(3) at 300K a...

    Text Solution

    |

  9. For a spontaneous reaction, DeltaG , equilibrium constant (K) and E(ce...

    Text Solution

    |

  10. An ideal gas is allowed to expand both reversibly and irreversibly in ...

    Text Solution

    |

  11. In conversion of lime-stone to lime, CaCO(3(s)) to CaO((s)) + CO(2(g...

    Text Solution

    |

  12. Standard entropy of X(2) , Y(2) and XY(3) are 60, 40 and 50JK^(-1)mol...

    Text Solution

    |

  13. Which one of the following statement is false?

    Text Solution

    |

  14. In thermodynamics, a process is called reversible when

    Text Solution

    |

  15. One mole of a non-ideal gas undergoes a change of state (2.0atm,3.0L,9...

    Text Solution

    |

  16. Two moles of an ideal gas expanded isothermally and reversibly from 1L...

    Text Solution

    |

  17. The enthalpy of vaporisation of a liquid is 30 kJ mol^(-1) and entropy...

    Text Solution

    |

  18. When 1mol of a monoatomic ideal gas at TK undergoes adiabatic change u...

    Text Solution

    |

  19. The direct conversion of A to B is difficult, hence it is carried out ...

    Text Solution

    |

  20. For the process H(2)O(l) (1 "bar", 373 K) rarr H(2)O(g) (1"bar", 373 K...

    Text Solution

    |