Critical solution temperature (or the consolute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which
A homogeneous solution (say of phenol water) is formed
Mutual solubility of the two liquids shows a decreasing trend
Two liquids are completely separated into two layers
None of these
Correct Answer :
A. A homogeneous solution (say of phenol water) is formed
Related Questions
Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K
0
∞
50
100
__________ does not change during phase transformation processes like sublimation, melting & vaporisation.
Entropy
Gibbs free energy
Internal energy
All (A), (B) & (C)
The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
∞
1
0
-ve
The temperature at the eutectic point of the system is the __________ temperature that can be attained in the system.
Lowest
Highest
Average
None of these
What is the ratio of adiabatic compressibility to isothermal compressibility?
1
< 1
> 1
>> 1
Gibbs free energy at constant pressure and temperature under equilibrium conditions is
∞
0
Maximum
Minimum
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
While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is
Infinity
Unity
Constant
Negative
Sublimation temperature of dry ice (solid CO2) is __________ °C.
-273
0
-78
5
A gas has a volume of 27.3 c.c. at 0°C. Its volume at 10°C (if pressure remains unchanged) will be __________ c.c.
2.73
28.3
273
283
For an ideal liquid solution, which of the following is unity?
Activity
Fugacity
Activity co-efficient
Fugacity co-efficient
When a gas is expanded from high pressure region to low pressure region; temperature change occurs. This phenomenon is related to the
Gibbs-Duhem equation
Gibbs-Helmholtz equation
Third law of thermodynamics
Joule-Thomson effect
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
Isotherm on an enthalpy-concentration diagram, for an ideal solution will be a
Straight line
Sine curve
Parabola
Hyperbola
In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is
A . x22
Ax1
Ax2
Ax12
Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will
Increase
Decrease
Remain unchanged
First fall and then rise
Activity co-efficient is a measure of the
Departure from ideal solution behaviour
Departure of gas phase from ideal gas law
Vapour pressure of liquid
None of these
In the reaction; N2 + O2 2NO, increasing the pressure will result in
Shifting the equilibrium towards right
Shifting the equilibrium towards left
No change in equilibrium condition
None of these
The root mean square speed of molecules of a gas is equal to (where, m = mass of the molecule K = Boltzmanns constant, T = absolute temperature)
√(2KT/m)
√(3KT/m)
√(6KT/m)
3KT/m
In a reversible process
Tds = dE + dW
dE - dW = Tds
dW - dE = Tds
Tds - dW + dE >0
Which is a state function?
Specific volume
Work
Pressure
Temperature
Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in
Increased COP
Same COP
Decreased COP
Increased or decreased COP; depending upon the type of refrigerant
Pick out the correct statement.
The available energy in an isolated system for all irreversible (real) processes decreases
The efficiency of a Carnot engine increases, if the sink temperature is decreased
The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy
All (A), (B) and (C)
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
Refrigeration capacity of a household refrigerator may be round about __________ tons.
0.15
1.5
4.5
6.5
The ammonia synthesis reaction represented by N2 + 3H2 2NH3; ΔH = - 22.4 kcal, is
Endothermic
Exothermic
Isothermal
Adiabatic
A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is
Zero
Positive
Negative
None of these
The change in Gibbs free energy for vaporisation of a pure substance is
Positive
Negative
Zero
May be positive or negative
Reduced pressure of a gas is the ratio of its
Pressure to critical pressure
Critical pressure to pressure
Pressure to pseudocritical pressure
Pseudocritical pressure to pressure