Advertisements
Advertisements
प्रश्न
What is the usual definition of entropy?
उत्तर
- Entropy is a thermodynamic state function that is a measure of the randomness or disorderliness of the system.
- For a reversible change taking place at a constant temperature (T). the change in entropy
- The system is equal to heat energy absorbed or evolved (q) by the system divided by the constant temperature (T).
`Δ"S"_"sys" = "q"_"rev"/"T"`
APPEARS IN
संबंधित प्रश्न
The correct thermodynamic conditions for the spontaneous reaction at all temperature is
∆S is expected to be maximum for the reaction
Identify the state and path functions out of the following:
- Enthalpy
- Entropy
- Heat
- Temperature
- Work
- Free energy
State the various statements of the second law of thermodynamics.
What are spontaneous reactions?
1 mole of an ideal gas, maintained at 4.1 atm and at a certain temperature, absorbs heat 3710 J and expands to 2 litres. Calculate the entropy change in the expansion process.
30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK−1 mol−1. Calculate the melting point of sodium chloride.
You are given normal boiling points and standard enthalpies of vapourisation. Calculate the entropy of vapourisation of liquids listed below.
| Liquid | Boiling points (°C) | ΔH (kJ mol−1) |
| Ethanol | 78.4 | + 42.4 |
Calculate the enthalpy of hydrogenation of ethylene from the following data.
Bond energies of C − H, C − C, C = C and H − H are 414, 347, 618 and 435 kJ mol−1.
For the reaction at 298 K: \[\ce{2A + B -> C}\]
ΔH = 400 KJ mol−1; ΔS = 0.2 KJ K−1 mol−1 Determine the temperature at which the reaction would be spontaneous.
