For a thermodynamic system containing 'x' chemical species, the maximum number of phases that can co-exist at equilibrium is
x
x + 1
x + 2
x + 3
Correct Answer :
C. x + 2
Related Questions
Gibbs free energy per mole for a pure substance is equal to the
Latent heat of vaporisation
Chemical potential
Molal boiling point
Heat capacity
Enthalpy of a gas depends upon its
Temperature
Mass
Volume
Pressure
Claude gas liquefaction process employs cooling
At constant pressure
By throttling
By expansion in an engine
None of these
The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is
100,000 kW
160,000 kW
200,000 kW
320,000 kW
Pick out the wrong statement.
An ideal liquid or solid solution is defined as one in which each component obeys Raoult's law
If Raoult's law is applied to one component of a binary mixture; Henry's law or Raoult's law is applied to the other component also
Henry's law is rigorously correct in the limit of infinite dilution
None of these
Pick out the wrong statement.
Enthalpies of all elements in their standard states are assumed to be zero
Combustion reactions are never endothermic in nature
Heat of reaction at constant volume is equal to the change in internal energy
Clausius-Clapeyron equation is not applicable to melting process
In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v23 m3) is maximum, when the value of 'n' is
0
1
y = 1.44
1.66
Sound waves propagation in air exemplifies an __________ process.
Adiabatic
Isothermal
Isometric
None of these
Fugacity co-efficient of a substance is the ratio of its fugacity to
Mole fraction
Activity
Pressure
Activity co-efficient
__________ does not change during phase transformation processes like sublimation, melting & vaporisation.
Entropy
Gibbs free energy
Internal energy
All (A), (B) & (C)
Compressibility factor-reduced pressure plot on reduced co-ordinates facilitates
Use of only one graph for all gases
Covering of wide range
Easier plotting
More accurate plotting
Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as
P + F - C = 2
C = P - F + 2
F = C - P - 2
P = F - C - 2
Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)
(atm)Δx, when Δx is negative
(atm)Δx, when Δx is positive
Dimensionless, when Δx = 0
(atm)Δx2, when Δx > 0
Entropy, which is a measure of the disorder of a system, is:
Independent of pressure
Independent of temperature
Zero at absolute zero temperature for a perfect crystalline substance
All (A), (B) & (C)
Gibbs-Helmholtz equation is
ΔF = ΔH + T [∂(ΔF)/∂T]P
ΔF = ΔH - TΔT
d(E - TS) T, V < 0
dP/dT = ΔHvap/T.ΔVvap
Which of the following non-flow reversible compression processes require maximum work?
Adiabatic process
Isothermal process
Isobaric process
All require same work
When dilute aqueous solutions of two salts are mixed, the process is associated with
Decrease in temperature
Increase in temperature
No change in temperature
Change in temperature which is a function of composition
Pick out the wrong statement
Phase rule variables are intensive properties
Heat and work are both state function
The work done by expansion of a gas in vacuum is zero
CP and CV are state function
Normal temperature and pressure (N.T.P.) corresponds to
0°C and 760 mm Hg
15°C and 760 mm Hg
20°C and 760 mm Hg
0°C and 1 kgf/cm2
A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is
349
651
667
1000
(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)
First law of thermodynamics deals with the
Direction of energy transfer
Reversible processes only
Irreversible processes only
None of these
An isentropic process is carried out at constant
Volume
Pressure
Temperature
All (A), (B) and (C)
Which of the following will increase the volume of a real gas by four times?
Doubling the absolute temperature as well as pressure of the gas
Reducing pressure to one fourth at constant temperature
Reducing temperature to one fourth at constant pressure
Reducing the temperature to half and doubling the pressure
The value of gas constant 'R' is
1.987 cal/gm mole °K
1.987 BTU/lb. mole °R
Both (A) and (B)
Neither (A) nor (B)
COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about
0.5
3.5
4.5
8.5
Internal energy change of a system over one complete cycle in a cyclic process is
Zero
+ve
-ve
Dependent on the path
The free energy change for a chemical reaction is given by (where, K = equilibrium constant)
RT ln K
-RT ln K
-R ln K
T ln K
If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as
Solubility increases as temperature increases
Solubility increases as temperature decreases
Solubility is independent of temperature
Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
Melting of ice is an example of an __________ process.
Adiabatic
Isothermal
Isometric
None of these