Q.Which has greater entropy at 400 K, N2 or NH3?

Ice has the minimum entropy among water, ice, and water vapour, because solids are the most ordered state of matter.

Entropy (S) is a measure of the randomness or disorder of a system. For the same substance, entropy increases in the order solid < liquid < gas, because molecules in a solid are locked in a fixed, highly ordered lattice with only vibrational motion, molecules in a liquid have more freedom to move past one another (more disorder), and molecules in a gas move almost independently and randomly (maximum disorder).

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For a real (spontaneous) process in an isolated system with ΔU = 0, ΔS is positive (ΔS > 0).

By the second law of thermodynamics, the entropy of an isolated system can never decrease. For any spontaneous (irreversible) process it increases (ΔS > 0); only for a hypothetical reversible process does it stay constant (ΔS = 0). Since ΔU = 0 defines an isolated system, entropy …

Entropy (S) is a thermodynamic state function measuring disorder; for a reversible process its change is defined as $\Delta S = \frac{q_{rev}}{T}$, which is option (d).

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Entropy has the unit joule per kelvin (J K^-1), or J K^-1 mol^-1 on a molar basis.

Entropy (S) is defined thermodynamically by the relation dS = q_rev / T, where q_rev is heat absorbed reversibly (in joules) and T is the absolute temperature (in kelvin).

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The Second Law of Thermodynamics states that the entropy of the universe is always increasing (option b) for spontaneous processes.

Entropy (S) is a measure of disorder/randomness. The Second Law of Thermodynamics states that for any spontaneous process, the total entropy of the universe (dS_universe = dS_system + dS_surroundings) always increases; it never decreases. Only for a perfectly reversible process does the total entropy remain unchanged ( …

The statement is Wrong: it is a perfectly crystalline solid at absolute zero (0 K) whose entropy is zero - not a gaseous substance.

Entropy is a measure of disorder/randomness. Gas molecules move randomly and rapidly in all directions, so gases are the MOST disordered state of matter and have the HIGHEST entropy of the three states, not zero. The Third Law of Thermodynamics instead says that the entropy of a perfect crystalline substance (atoms/ions arranged in one single, perfectly ordered pattern) approaches zero as the temperature approaches absolute zero (0 K), because at that point there is essentially onl …

The entropy of the universe always increases for any spontaneous process — this is the Second Law of Thermodynamics.

Entropy (S) is a measure of the randomness or disorder of a system. The second law of thermodynamics states that for any spontaneous process, the total entropy change of the universe ($\Delta S_{total} = \Delta S_{system} + \Delta S_{surroundings}$) is always positive, i.e., entropy alw …

Entropy (S) is defined via dS = q(rev)/T, so its unit is energy divided by temperature: joule per kelvin (J/K), or J K^-1 mol^-1 for molar entropy.

Entropy change is defined as deltaS = q(reversible)/T, where q is heat exchanged reversibly and T is the absolute temperature. Since heat is measured in joules and temperature in kelvin, the unit of e …

NH3 has higher entropy than N2 because entropy depends on the number of ways energy can be distributed among a molecule's motions, and a more complex (more atoms, non-linear) molecule has more such ways.

Entropy (S) is a measure of the randomness or disorder of a system, which in molecular terms corresponds to the number of accessible microstates. For gas-phase molecules, this includes translational, rotational, and vibrational degrees of freedom.

• N2 is a simple linear diatomic molecule: it has only 1 rotational degree of freedom (about an axis perpendicular to the bond) and 1 vibrational mode.
• NH3 is a non-linear, pyramidal molecule with 4 atoms: it has 3 rotational degrees of freedom and 6 vibrational modes (3N-6 = 3x4-6 = 6). …

Entropy is the thermodynamic quantity built specifically to measure how disordered/random a system's arrangement is.

Among thermodynamic quantities:

• Free energy (Gibbs energy, G) measures the maximum useful (non-expansion) work obtainable from a process at constant T and P, and predicts spontaneity.
• Internal energy (U) is the total energy content of a system (kinetic + potential energy of its particles). …

Entropy (S) is a state function measuring the randomness/disorder of a system — it increases as disorder increases (e.g., solid → liquid → gas).

Entropy is defined thermodynamically via dS = q_rev/T (the reversible heat exchanged divided by temperature). Physically, it reflects the number of ways a system's particles can be arranged — greater disorder (more possible microscopic arrangements) means higher entropy. Gases have higher entropy than liquids, which have higher entropy than solids, because molecular motion becomes more random going from solid to ga …