Advertisements
Advertisements
प्रश्न
What are the conditions for the spontaneity of a process?
उत्तर
- The spontaneity of any process depends on three different factors.
- If the enthalpy change of a process is negative, then the process is exothermic and may be spontaneous. (∆H is negative)
- If the entropy change of a process is positive, then the process may occur spontaneously. (∆S is positive)
- The Gibbs free energy which is the combination of the above two (∆H – T∆S) should be negative for a reaction to occur spontaneously, i.e. the necessary condition for a reaction to being spontaneous is ∆H – T∆S < 0
- For spontaneous process, ∆Stotal > 0, ∆G < 0, ∆S < 0
APPEARS IN
संबंधित प्रश्न
Define is Gibb’s free energy.
The equilibrium constant of a reaction is 10, what will be the sign of ∆G? Will this reaction be spontaneous?
List the characteristics of Gibbs free energy.
For the reaction \[\ce{Ag2O_{(s)} -> 2Ag_{(s)} + 1/2O2_{(g)}}\]: ΔH = 30.56 kJ mol−1 and ΔS = 6.66 JK−1 mol−1 (at 1 atm). Calculate the temperature at which ΔG is equal to zero. Also predict the direction of the reaction
- at this temperature and
- below this temperature.
What is the equilibrium constant Keq for the following reaction at 400 K?
\[\ce{2NOCl_{(g)} ⇌ 2NO_{(g)} + Cl2_{(g)}}\], given that H0 = 77.2 kJ mol−1 and ∆S0 = 122 JK−1 mol−1
When 1-pentyne (A) is treated with 4N alcoholic KOH at 175°C, it is converted slowly into an equilibrium mixture of 1.3% 1-pentyne (A), 95.2% 2-pentyne (B) and 3.5% of 1, 2 pentadiene (C) the equilibrium was maintained at 175°C, calculate ΔG0 for the following equilibria.
\[\ce{B ⇌ A}\] `Δ"G"_1^0` = ?
\[\ce{B ⇌ C}\] `Δ"G"_2^0` = ?
At 33K, N2O4 is fifty percent dissociated. Calculate the standard free energy change at this temperature and at one atmosphere.
Find out the value of the equilibrium constant for the following reaction at 298 K, \[\ce{2NH3_{(g)} + CO2_{(g)} ⇌ NH2CONH2_{(aq)} + H2O_{(l)}}\] Standard Gibbs energy change, `∆"G"_"r"^0` at the given temperature is –13.6 kJ mol−1.
