Home
Class 11
CHEMISTRY
Comment on the spontaneity of a reaction...

Comment on the spontaneity of a reaction at constant temperature and pressure in the following cases. (i)`DeltaH lt 0` and `DeltaS gt 0` (ii) `DeltaH gt0` and `Delta S lt 0` (iii) `DeltaH lt 0` and `DeltaS lt 0` (iv)`DeltaH gt 0` and`DeltaS gt 0`

Text Solution

Verified by Experts

(i) Both energy factor and randomness factor favour the process. Hene, reaction will be always spontaneous.
(ii)Both factors opposes the process. Hence, reaction would be always non-spontaneous.
(iii) Energy factor favour but randomness factor opposes. For process to be spontaneous , opposing factor should be smaller, i.e., `T DeltaS lt DeltaH`. Hence, reaction is spontaneous at low temperature andnon- spontaneous at high temperature.
(iv) Energy factor opposes but randomness factor . For spontaneity, `T DeltaS gt DeltaH`. Hence, reaction is spontaneous at high temperature and non-spontaneous at low temperature.
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS

    PRADEEP|Exercise NCERT EXEMPLAR PROBLEMS WITH ANSWERS, HINTS AND SOLUTIONS( MULTIPLE CHOICE QUESTIONS-I)|14 Videos

  • THERMODYNAMICS

    PRADEEP|Exercise NCERT EXEMPLAR PROBLEMS WITH ANSWERS, HINTS AND SOLUTIONS( MULTIPLE CHOICE QUESTIONS-II)|5 Videos

  • THERMODYNAMICS

    PRADEEP|Exercise NCERT QUESTIONS AND EXERCISES WITH ANSWERS|22 Videos

  • STRUCTURE OF ATOM

    PRADEEP|Exercise Competition Focus (JEE (Main and Advanced)/Medical Entrance (IX. Assertion And Reason Type Questions (Type II))|12 Videos

Similar Questions

Explore conceptually related problems

A porcess is nonspontaneous at evey temperature if (i) Delta H gt 0, Delta S = 0 (ii) Delta H lt 0, Delta S gt 0 (iii) Delta H gt 0, Delta S lt 0 (iv) Delta H = 0, Delta S lt 0

DeltaH gt DeltaE for the reaction

Derive relationship between DeltaH and DeltaU .Give example when (i) DeltaH lt DeltaU (ii) DeltaH = DeltaU (iii) DeltaH gt DeltaU

A chemical reaction with Delta H gt0 carried out at constant temperature and pressure will necessarily be spontaneous if

Expalin the state of chemical reactions when : (i) DeltaG =0 (ii) DeltaG lt 0 and (iii) DeltaG gt 0

What will be the states of a chemical reaction when: DeltaG = 0" "(ii) DeltaG gt 0 " " DeltaG lt 0

A change in the free energy of a system at constant temperature and pressure will be: Delta_(sys)G = Delta_(sys)H -T Delta_(sys)S At constant temperature and pressure Delta_(sys) G lt 0 (spontaneous) Delta_(sys)G = 0 (equilibrium) Delta_(sys)G gt 0 (non-spontaneous) If both DeltaH and Deltas are negative, the reaction will be spontaneous

If Delta H gt 0 and Delta S gt 0 , the reaction proceeds spontaneously when :-

A change in the free energy of a system at constant temperature and pressure will be: Delta_(sys)G = Delta_(sys)H -T Delta_(sys)S At constant temperature and pressure Delta_(sys) G lt 0 (spontaneous) Delta_(sys)G = 0 (equilibrium) Delta_(sys)G gt 0 (non-spontaneous) The free enegry for a reaction having DeltaH = 31400 cal, DeltaS = 32 cal K^(-1) mol^(-1) at 1000^(@)C is