The first law of thermodynamics is a restatement of the law of conservation of
Mass
Energy
Momentum
None of these
Correct Answer :
B. Energy
Related Questions
Filling of gas from a high pressure cylinder into small bottles is an example of a/an __________ process.
Equilibrium
Adiabatic
Steady
Unsteady
Number of degrees of freedom for a three phase system in equilibrium comprising of three nonreacting chemical species is
2
0
1
3
Gibbs phase rule finds application, when heat transfer occurs by
Conduction
Convection
Radiation
Condensation
Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.
Fugacity
Partial pressure
Activity co-efficient
All (A), (B), and (C)
Claude's liquefaction process employs the cooling of gases by
Expansion in an engine
Following a constant pressure cycle
Throttling
None of these
As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches
Unity
Zero
That of the heat of reaction
Infinity
Which of the following has the least thermal efficiency?
Steam engine
Carnot engine
Diesel engine
Otto engine
Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.
Infinity
Minus infinity
Zero
None of these
If heat contents of CH4, C2H4 and C3H8 are -17.9, 12.5 and -24.8 kcal/mole respectively, than ΔH for the reaction CH4(g) + C2H4(g) C3H8(g) will be __________ Kcal.
-19.4
-30.2
55.2
-55.2
In the decomposition of PCl5 represented by, PCl5 PCl3 + Cl2, decrease in the pressure of the system will __________ the degree of dissociation of PCl5.
Increase
Decrease
Not alter
None of these
The internal energy of an ideal gas is a function of its __________ only.
Molecular size
Volume
Pressure
Temperature
Pick out the wrong statement.
A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.
An open system permits exchange of both mass and energy with its surroundings
The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics
None of the above
At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is
1.572
1.9398
3.389
4.238
The reaction A (l) → R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The numbers of degrees of freedom are:
1
2
3
0
Co-efficient of Performance (COP) of a refrigerator is the ratio of the
Work required to refrigeration obtained
Refrigeration obtained to the work required
Lower to higher temperature
Higher to lower temperature
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature.
Critical
Boyle
Inversion
Reduced
Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called __________ solutions.
Ideal
Real
Isotonic
None of these
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature.
Boyle
Inversion
Critical
Reduced
Which of the following is an undesirable characteristic of a refrigerant?
It should be non-explosive
It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils
Its vapor pressure at the condenser temperature should be very high
None of these
For the reversible exothermic reaction, N2 + 3H2 2NH3, increase of pressure would
Shift the equilibrium towards right
Give higher yield of NH3
Both (B) and (C)
Neither (A) nor (B)
Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.
Isothermal
Adiabatic
Isentropic
None of these
Pick out the wrong statement.
The chemical potential of a pure substance depends upon the temperature and pressure
The chemical potential of a component in a system is directly proportional to the escaping tendency of that component
The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature
The chemical potential of species 'i' in the mixture (μi) is mathematically represented as,μi = ∂(nG)/∂ni]T,P,nj where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. 'G' is Gibbs molar free energy
Extensive properties of a thermodynamic system depend upon the __________ of the system.
Specific volume
Temperature
Mass
Pressure
__________ decreases during adiabatic throttling of a perfect gas.
Entropy
Temperature
Enthalpy
Pressure
Clapeyron Equation deals with the
Rate of change of vapour pressure with temperature
Effect of an inert gas on vapour pressure
Calculation of ΔF for spontaneous phase change
Temperature dependence of heat of phase transition
Heat is added at constant pressure in an ideal __________ cycle.
Stirling
Brayton
Rankine
Both (B) and (C)
Which of the following identities can be most easily used to verify steam table data for superheated steam?
(∂T/∂V)S = (∂p/∂S)V
(∂T/∂P)S = (∂V/∂S)P
(∂P/∂T)V = (∂S/∂V)T
(∂V/∂T)P = -(∂S/∂P)T
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 fugacity of a gas in a mixture is equal to the product of its mole fraction and its fugacity in the pure state at the total pressure of the mixture. This is
The statement as per Gibbs-Helmholtz
Called Lewis-Randall rule
Henry's law
None of these
Pick out the correct statement.
Entropy and enthalpy are path functions
In a closed system, the energy can be exchanged with the surrounding, while matter cannot be exchanged
All the natural processes are reversible in nature
Work is a state function