In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
Correct Answer :
C. Tds - dE + dW < 0
Related Questions
Kopp's rule is used to calculate the heat capacity of
Solids
Liquids
Gases
All (A), (B) & (C)
If an ideal solution is formed by mixing two pure liquids in any proportion, then the __________ of mixing is zero
Enthalpy
Volume
Both 'a' & 'b'
Neither 'a' nor 'b'
Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is
2
0
1
3
Clausius-Clapeyron Equation gives accurate result, when the
Vapour pressure is relatively low and the temperature does not vary over wide limits
Vapour obeys the ideal gas law and the latent heat of vaporisation is constant
Volume in the liquid state is negligible compared with that in the vapour state
All (A), (B) and (C)
At the critical point of a substance
The surface tension vanishes
Liquid and vapour have the same density
There is no distinction between liquid and vapour phases
All (A), (B) and (C)
The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process.
Isobaric
Isothermal
Adiabatic
None of these
The equation DU = Tds - PdV is applicable to infinitesimal changes occuring in
An open system of constant composition
A closed system of constant composition
An open system with changes in composition
A closed system with changes in composition
The thermodynamic law, PVy = constant, is not applicable in case of
Ideal compression of air
Free expansion of an ideal gas
Adiabatic expansion of steam in a turbine
Adiabatic compression of a perfect gas
In an ideal refrigeration cycle, the change in internal energy of the fluid is
+ve
-ve
0
Either of the above three; depends on the nature of refrigerant
Which of the following processes cannot be made reversible even under ideal condition of operation?
Free expansion of a gas
Compression of air in a compressor
Expansion of steam in a turbine
All (A), (B) & (C)
For an ideal gas, the chemical potential is given by
RT d ln P
R d ln P
R d ln f
None of these
Forward reaction will be favoured for the exothermic reaction, represented by CO + H2O CO2 + H2, by
Low temperature and high pressure
Low temperature and low pressure
High temperature and high pressure
High temperature and low pressure
It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.
The amount of work needed is path dependent
Work alone cannot bring out such a change of state
The amount of work needed is independent of path
More information is needed to conclude anything about the path dependence or otherwise of the work needed
The partial pressure of each constituent present in an alloy is __________ the total vapor pressure exerted by the alloy.
Less than
Equal to
More than
Either (B) or (C); depends on the type of alloy
A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P1 and P2. (where, P1 and P2 are initial and final pressures respectively)
Logarithmic
Arithmetic
Geometric
Harmonic
At absolute zero temperature, the __________ of the gas is zero.
Pressure
Volume
Mass
None of these
A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is
Zero
Positive
Negative
None of these
Critical compressibility factor for all substances
Are more or less constant (vary from 0.2 to 0.3)
Vary as square of the absolute temperature
Vary as square of the absolute pressure
None of these
Sublimation temperature of dry ice (solid CO2) is __________ °C.
-273
0
-78
5
A gas can be liquefied by pressure alone only, when its temperature is __________ its critical temperature.
Less than
More than
Equal to or higher than
Less than or equal to
Fugacity and pressure are numerically equal, when the gas is
In standard state
At high pressure
At low temperature
In ideal state
The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
Freezing
Triple
Boiling
Boyle
Variation of equilibrium pressure with temperature for any two phases of a given substances is given by the __________ equation.
Gibbs-Duhem
Maxwell's
Clapeyron
None of these
(1/V) (∂V/∂T)P is the mathematical expression
Joule-Thomson co-efficient
Specific heat at constant pressure (Cp)
co-efficient of thermal expansion
Specific heat at constant volume (CV)
The expression, nCv(T2 - T1), is for the __________ of an ideal gas.
Work done under adiabatic condition
Co-efficient of thermal expansion
Compressibility
None of these
One ton of refrigeration capacity is equivalent to the heat removal rate of
50 kcal/hr
200 BTU/hr
200 BTU/minute
200 BTU/day
Enthalpy 'H' is defined as
H = E - PV
H = F - TS
H - E = PV
None of these
An irreversible process
Is the analog of linear frictionless motion in machines
Is an idealised visualisation of behaviour of a system
Yields the maximum amount of work
Yields an amount of work less than that of a reversible process
A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of
Temperature only
Temperature and pressure only
Temperature, pressure and liquid composition xi only
Temperature, pressure, liquid composition xi and vapour composition yi
Entropy of an ideal gas depends upon its
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)