A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1 is
For organic compounds, group contribution method can be used for the estimation of
Two substances are in equilibrium in a reversible chemical reaction. If the concentration of each substance is doubled, then the value of the equilibrium constant will be
One fourth of its original value
Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)?
At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.
May increase or decrease; depends on the gas
The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
Extensive properties of a thermodynamic system depend upon the __________ of the system.
In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants)
Addition of inert gas favours the forward reaction, when Δx is positive
Pressure has no effect on equilibrium, when Δn = 0
Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)
As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches
That of the heat of reaction
Entropy change of mixing two liquid substances depends upon the
Quantity (i.e. number of moles)
Fugacity is a measure of the
Escaping tendencies of the same substance in different phases of a system
Relative volatility of a mixture of two miscible liquids
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:
Pick out the wrong statement.
Activity co-efficient is dimensionless.
In case of an ideal gas, the fugacity is equal to its pressure.
In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.
The fugacity co-efficient is zero for an ideal gas
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature.
Melting of wax is accompanied with __________ in entropy.
The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is
Data insufficient, can't be predicted
Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are
Same at the same reduced temperature
Same at the same reduced pressure
Joule-Thomson Co-efficient at any point on the inversion curve is
For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.
The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv), depends upon its
Isobaric process means a constant process.
The specific heat of saturated water vapour at 100°C is
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
What is the value of ln y (where y = activity co-efficient) for ideal gases?
Gibbs free energy at constant pressure and temperature under equilibrium conditions is
Which of the following has the least thermal efficiency?
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
Refrigerants commonly used for domestic refrigerators are
Ethyl chloride or methyl chloride
Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the
Cold reservoir approaches zero
Hot reservoir approaches infinity
In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process.