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At 27^(@)C for reaction, C(6)H(6)(l)+(...

At `27^(@)C` for reaction,
`C_(6)H_(6)(l)+(15)/(2)O_(2)(g)to6CO_(2)(g)+3H_(2)O(l)`
proceeds spontaneously because the magnitude of

A

`DeltaH = T Delta S`

B

`DeltaH gt T Delta S`

C

`DeltaH lt T Delta S`

D

`DeltaH gt 0` and `T Delta S lt 0`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the given reaction and the thermodynamic principles involved. The reaction is: \[ C_6H_6(l) + \frac{15}{2} O_2(g) \rightarrow 6 CO_2(g) + 3 H_2O(l) \] ### Step 1: Understanding the Reaction This reaction represents the combustion of benzene (C6H6) in the presence of oxygen (O2), producing carbon dioxide (CO2) and water (H2O). ### Step 2: Determine the Signs of ΔH and ΔS - **ΔH (Enthalpy Change)**: For combustion reactions, ΔH is typically negative because energy is released when the bonds in the reactants are broken and new bonds are formed in the products. - **ΔS (Entropy Change)**: To determine the sign of ΔS, we need to compare the number of gaseous moles on the reactant side and the product side. ### Step 3: Count the Moles of Gas - **Reactants**: - 1 mole of C6H6 (liquid, does not contribute to gas moles) - \( \frac{15}{2} \) moles of O2 (gas) - Total gas moles = \( \frac{15}{2} = 7.5 \) moles - **Products**: - 6 moles of CO2 (gas) - 3 moles of H2O (liquid, does not contribute to gas moles) - Total gas moles = 6 moles of CO2 ### Step 4: Calculate ΔS - The total moles of gas in the reactants = 7.5 moles - The total moles of gas in the products = 6 moles Since there are fewer gaseous moles in the products than in the reactants, ΔS is negative. ### Step 5: Apply the Gibbs Free Energy Equation The Gibbs free energy change (ΔG) is given by: \[ \Delta G = \Delta H - T \Delta S \] For the reaction to be spontaneous, ΔG must be negative: \[ \Delta G < 0 \] This implies: \[ \Delta H - T \Delta S < 0 \] Rearranging gives: \[ \Delta H < T \Delta S \] ### Step 6: Analyze the Conditions for Spontaneity Since ΔH is negative and ΔS is negative, for the reaction to be spontaneous, we need: \[ \Delta H > T \Delta S \] This means that the magnitude of ΔH must be greater than the magnitude of TΔS (considering that TΔS is a negative value). ### Conclusion The correct option is: **ΔH > TΔS**

To solve the problem, we need to analyze the given reaction and the thermodynamic principles involved. The reaction is: \[ C_6H_6(l) + \frac{15}{2} O_2(g) \rightarrow 6 CO_2(g) + 3 H_2O(l) \] ### Step 1: Understanding the Reaction This reaction represents the combustion of benzene (C6H6) in the presence of oxygen (O2), producing carbon dioxide (CO2) and water (H2O). ### Step 2: Determine the Signs of ΔH and ΔS ...
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DINESH PUBLICATION-CHEMICAL THERMODYNAMICS AND CHEMICAL ENERGETICS -Exercise
  1. For a hypothetical reaction A+B to C if DeltaG^(@) gt 0

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  2. The free energy change for a reversible reaction at equilibrium is

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  3. At 27^(@)C for reaction, C(6)H(6)(l)+(15)/(2)O(2)(g)to6CO(2)(g)+3H(2...

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  4. A particular reaction at 27^(@)C for which DeltaH gt 0 and DeltaS gt 0...

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  5. Which of the following expression defines the physical significance of...

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  6. A gas is allowed to expand reversibly under adiabatic conditions. What...

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  7. The hypothetical gaseous reaction A+B to AB

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  8. For a process H(2)O(s) rarr H(2)O(l) at 273 K

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  9. For the process "Dry ice" to CO(2)(g)

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  10. The non- expansion work of a system

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  11. For the percipitation reaction of Ag^(o+) ions with NaCI, which of the...

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  12. Heat of neutralisation of NaOH and HCl is -57.46 kJ // equivalent. The...

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  13. The enthalpy change for a given reaction at 298 K is -x cal mol^(-1). ...

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  14. One litre-atmosphere is approximately equal to

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  15. The heat change at constant volume for the decomposition of silver (I)...

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  16. The maximum efficiency of a steam engine operating between 110^(@)C an...

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  17. What per cent T(1) is of T(2) for a heat engine whose efficiency is 10...

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  18. An engine operating between 100^(@)C and 0^(@)C takes 453.6 kcal of he...

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  19. Theheat capacity of liquid water at constant pressure, C(P) is 18 cal ...

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  20. A gas is allowed to expand at constant temperature from a volume of 1....

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