Change of heat content when one mole of compound is burnt in oxygen at constant pressure is called the
Calorific value
Heat of reaction
Heat of combustion
Heat of formation
Correct Answer :
C. Heat of combustion
Related Questions
Consider the reaction, C + O2 CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2?
-94 kcal
+94 kcal
> 94 kcal
< -94 kcal
Refrigerants commonly used for domestic refrigerators are
Ethyl chloride or methyl chloride
Freon-12
Propane
NH3 or CO2
A refrigerator may be termed as a
Heat pump
Heat engine
Carnot engine
None of these
In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc?
2HI H2 + I2
N2O4 2NO2
2SO2 + O2 2SO3
None of these
Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.).
Entropy
Internal energy
Enthalpy
Gibbs free energy
When a system in equilibrium is subjected to a change in temperature, pressure or concentration, the equilibrium is displaced in a direction which tends to undo the effect of the change. This is called the
Le-Chatelier principle
Kopp's rule
Law of corresponding state
Arrhenius hypothesis
When a system is in equilibrium for all possible processes, the differential or finite change of entropy is
< 0
> 0
= 0
None of these
(∂H/∂T)P is the mathematical expression for
CV
Entropy change
Gibbs free energy
None of these
After throttling, gas temperature
Decreases
Increases
Remain same
May increase or decrease; depends on the nature of the gas
A large iceberg melts at the base, but not at the top, because of the reason that
Ice at the base contains impurities which lowers its melting point
Due to the high pressure at the base, its melting point reduces
The iceberg remains in a warmer condition at the base
All (A), (B) and (C)
The heat capacities for the ideal gas state depend upon the
Pressure
Temperature
Both (A) & (B)
Neither (A) nor (B)
Change of state namely evaporation condensation, freezing and melting is an __________ process.
Isothermal
Adiabatic
Isobaric
Isochoric
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
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
In the reaction, H2 +I2 2HI, addition of an inert gas will
Increase the partial pressure of H2
Increase the partial pressure of I2
Increase the total pressure and hence shift the equilibrium towards the right
Not affect the equilibrium conditions
Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is
0
1
∞
None of these
__________ explains the equilibrium constant for any chemical reaction.
Henry's law
Law of mass action
Hess's law
None of these
Refrigeration capacity of a household refrigerator may be round about __________ tons.
0.15
1.5
4.5
6.5
Fugacity co-efficient of a substance is the ratio of its fugacity to
Mole fraction
Activity
Pressure
Activity co-efficient
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
The minimum number of phases that can exist in a system is
0
1
2
3
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
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 correct statement.
Compression ratio of an Otto engine is comparatively higher than a diesel engine
Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio
Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat
Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work
Free energy change at equilibrium is
Zero
Positive
Negative
Indeterminate
Melting of ice is an example of an __________ process.
Adiabatic
Isothermal
Isometric
None of these
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
In an ideal solution, the activity of a component equals its
Mole fraction
Fugacity at the same temperature and pressure
Partial pressure
None of these
Which of the following is not correct for a reversible adiabatic process?
TVγ-1 = constant
p1-γ.TY = constant
PVγ = constant
None of these
Throttling (Joule-Thomson effect) process is a constant __________ process.
Enthalpy
Entropy
Pressure
None of these