Home
Class 11
CHEMISTRY
Match the sign of DeltaH and DeltaS give...

Match the sign of `DeltaH` and `DeltaS` given in List - I with the type of reacting given in List - II and select the correct option.
`{: ( "List-I", " List-II"),( "(P) +ve and + ve", " (1)Spontaneous at all temperatures.") , ("(Q)-ve and -ve" , "(2)Non spontaneous at all temperatures."),(" (R)+ve and -ve" , "(3)Spontaneous only at low temperature") , ( "(S)-ve and +ve" , " (4)Spontaneous only at high temperature."):}`

A

P-4, Q-2, R-3,S-1

B

P-3, Q-4,R-2, S-1

C

P -3, Q-4, R-1, S-2

D

P-4,Q-3, R-2, S-1

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question of matching the signs of ΔH (enthalpy change) and ΔS (entropy change) with their corresponding spontaneity conditions, we can use the Gibbs free energy equation: \[ \Delta G = \Delta H - T \Delta S \] Where: - ΔG < 0 indicates a spontaneous process. - ΔG > 0 indicates a non-spontaneous process. Now, let's analyze each case provided in List-I: ### Step 1: Analyze Each Case 1. **Case P: ΔH > 0 (positive) and ΔS > 0 (positive)** - Here, both ΔH and ΔS are positive. - For spontaneity, we need ΔG < 0: \[ \Delta G = \Delta H - T \Delta S \] At high temperatures, TΔS can outweigh ΔH, making ΔG negative. Thus, this process is spontaneous at high temperatures. - **Match:** P → 4 (Spontaneous only at high temperature) 2. **Case Q: ΔH < 0 (negative) and ΔS < 0 (negative)** - Here, both ΔH and ΔS are negative. - For spontaneity: \[ \Delta G = \Delta H - T \Delta S \] At low temperatures, ΔG can be negative since ΔH is negative and TΔS is also negative but less significant. Thus, this process is spontaneous at low temperatures. - **Match:** Q → 3 (Spontaneous only at low temperature) 3. **Case R: ΔH > 0 (positive) and ΔS < 0 (negative)** - Here, ΔH is positive and ΔS is negative. - For spontaneity: \[ \Delta G = \Delta H - T \Delta S \] Both terms are positive, meaning ΔG will always be positive regardless of temperature. Thus, this process is non-spontaneous at all temperatures. - **Match:** R → 2 (Non-spontaneous at all temperatures) 4. **Case S: ΔH < 0 (negative) and ΔS > 0 (positive)** - Here, ΔH is negative and ΔS is positive. - For spontaneity: \[ \Delta G = \Delta H - T \Delta S \] Both terms can lead to ΔG being negative, making the process spontaneous at all temperatures. - **Match:** S → 1 (Spontaneous at all temperatures) ### Final Matches - P → 4 - Q → 3 - R → 2 - S → 1 ### Conclusion Thus, the correct option is **D: P-4, Q-3, R-2, S-1**. ---
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Competition File (Matrix Matching Type Questions)|4 Videos
  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Competition File (Integer Type Questions)|6 Videos
  • THERMODYNAMICS

    MODERN PUBLICATION|Exercise Competition File MCQ|158 Videos
  • STRUCTURE OF ATOM

    MODERN PUBLICATION|Exercise Unit Practice Test|13 Videos

Similar Questions

Explore conceptually related problems

Match the column :- {:(,"Sign of" DeltaH&Delta"respectively",,"Nature of reaction",),(,-&-,P,"Spontaneous only at low temperture",),(,-&+,Q,"Spontaneous only at high temperature",),(,+&+,R,Spontaneous at all temperature,),(,+&-,S,"non spontaneous at all temperature",):}

Match the following in List-I with List II and select the corect option :- {:(,List-I,,List-II,),(a,K_(P)=Q,i,"Always nonspontaneous",),(b,TgtDeltaH//S,ii,"Isothrmal process",),(c,underset(DeltaS=_ve)(DeltaH=+ve),iii,"Equilibrium",),(d,q=_ve,iv,"spontaneous and endothermic",):}

(A) All exothermic reactions are spontaneous at room temperature. ltBrgt (R) DeltaG=-ve for above reactions and for spontaneous reactions DeltaG=-ve .

Predict the sign of DeltaG for the reaction at a very low temperature for which DeltaH is +ve and DeltaS is positive.

DeltaH and DeltaS are +ve . Under what conditions, process will be spontaneous?

Assertion : Many endothermic reactions which are non- spontaneous on increasing the temperature. Reason : Endothermic reactions become spontaneous at high temperature if DeltaS is +ve and TDeltaS gt DeltaH .