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प्रश्न
Define entropy.
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उत्तर
Entropy (S) is defined more precisely as a thermodynamic state function that measures the degree of randomness or disorder of the particles in a system.
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संबंधित प्रश्न
In which of the following, entropy of the system decreases?
Answer the following in one or two sentences.
Comment on the spontaneity of reactions for which ∆H is positive and ∆S is negative.
Obtain the relationship between ∆G° of a reaction and the equilibrium constant.
Answer the following question.
Although ΔS for the formation of two moles of water from H2 and O2 is –327J K–1, it is spontaneous. Explain.
(Given ΔH for the reaction is –572 kJ).
For a certain reaction ΔH° = 219 kJ and ΔS° = –21 J/K. Determine whether the reaction is spontaneous or nonspontaneous.
Answer the following question.
Determine whether the following reaction is spontaneous under standard state conditions.
2H2O(l) + O2(g) → 2H2O2(l)
if ΔH° = 196 kJ, ΔS° = –126 J/K, does it have a cross-over temperature?
Equilibrium constant for a reaction is 20. What is the value of ΔG° at 300 K? (R = 8 x 10-3 kJ)
One mole of NaCl(s) on melting absorbed 30.5 kJ of heat and its entropy increased by 28.8 J K−1. The melting point of NaCl is ____________.
Identify the INCORRECT statement.
For a process, entropy change of a system is expressed as ________.
For a reversible spontaneous change, ∆S is ____________.
Arrange the following in order of increasing entropy.
I. 1.0 mol H2O (298 K, 1 atm)
II. 1.0 mol H2O (270 K, 1 atm)
III. 1.0 mol H2O (400 K, 1 atm)
What is the entropy change (in J K−1 mol−1) when one mole of ice is converted into water at 0°C? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol−1 at 0°C)
In how many of the following, ∆S is positive?
i. Melting of ice
ii. Sublimation of iodine
iii. Dissolution of CuSO4 in water
iv. Condensation of water vapour
v. Dissociation of H2 molecule into atoms
vi. Conversion of carbon dioxide gas to dry ice
vii. Vaporization of acetone
In which of the following, ∆S is positive?
For the reaction:
\[\ce{2Cl_{(g)} -> Cl2_{(g)}}\]
Heat of combustion of C(s), H2(g) and C2H6(g) are −x1, −x2 and −x3 respectively. Hence heat of formation of C2H6(g) is ____________.
At what temperature, a chemical reaction will have the following values of ∆G, ∆S and ∆H?
∆G = −5.2 KJ mol−1, ∆H = 145.6 kJ mol−1, ∆S = −216 kJ mol−1
The H-H bond energy is 430 kJ mol-1 and Cl-Cl bond energy is 240 kJ mol-1. ΔfH for HCl is - 90 kJ, then H-Cl bond energy is ______.
For a reaction ΔH = - 30kJ and ΔS = - 45 JK-1, at what temperature reaction changes from spontaneous to non-spontaneous?
Write the correct condition for spontaneity in terms of Gibbs energy.
Identify whether the following pair have a larger entropy or not. If yes then Why?
C2H5OH(l) or C2H5OH(g)
Calculate ΔG for ΔH = − 110 kJ, ΔS = + 40 J K−1 at 400 K.
Calculate ΔG0 for the reaction
\[\ce{CH_{4(g)} + H_{2(g)}-> C2H_{6(g)}}\]
State whether the reaction is spontaneous or not. (Given: KP = 3.358 × 1017, T = 25° C, R = 8.314 × 10−3 kJK−1 moI−1)
Define second law of thermodynamics.
