Physical Chemistry - 3


1) The first law of thermodynamics is conservation of................... 

Ans. Energy


2) The change in entropy is.............

Ans. Positive in an irreversible change


3) Change in entropy depends.........

Ans. On the thermodynamic state


4) The Gibb's function G in thermodynamics is defined as G = H-TS. In an isothermal, isobaric, reversible process, G.............

Ans. remains constant but not zero


5) When applied to solar radiation, Planck's law reduces to Wien's law in the............ 

Ans. Ultraviolet region


6) According to Maxwell's law of distribution of velocities of molecules, the most probable velocity is........

Ans. Less than the root mean square velocity


7) In a micro canonical ensemble, a system A of fixed volume is in contact with a large reservoir B. Then.......

Ans. A can exchange neither energy nor particles with B


8) In a canonical ensemble, a system A of fixed volume is in contact with  a large reservoir B. Then.......

Ans. A can exchange only energy with B


9) In a grand canonical ensemble, a system A of fixed volume is in contact with a large reservoir B. Then.......

Ans. A can exchange both energy and particles with B


10) In case of Bose - Einsteinc .................

Ans. Number of particles increases in lower energy levels at low temperatures and high pressures


11) The quantum statistics reduces to classical statistics under the  following condition..............

Ans. ρ λ3 >> 1


12) According to Debye's theory of specific heat at high temperature specific heat is proportional to.......

Ans. Independent of T


13) According to Debye's theory of specific heat at low temperature specific heat is proportional to.......

Ans. T3


14) Specific heat of metals can be expressed as.................

Ans. AT + BT3


15) The term “thermodynamics” comes from the Greek words ‘therme’ and ‘dynamic which means _______.

Ans. Heat power


16) The term “thermodynamics” was first used in 1849 in the publication of a

Ans. Lord Kelvin


17) The electrons in an atom which rotate about the nucleus possess what kind of energy?

Ans. Rotational kinetic energy


18) The molecules of gas moving through space with some velocity possess what kind of energy?

Ans. Translational energy


19) What form of energy refers to those a system possesses as a whole with respect to some outside reference frame, such as potential and kinetic energies?

Ans. A macroscopic form of energy


20) What type of system energy is related to the molecular structure of a  system?

Ans. Microscopic form of energy


21) The sum of all the microscopic form of energy is called _____.

Ans. Internal energy


22) What does the term “uniform” mean?

Ans. No change with location


23) What is a process during which the specific volume remains constant?

Ans. Isochoric or isometric process


24) What is a process during which the pressure remains constant?

Ans. Isobaric process


25) What is a process with identical end states called?

Ans. Cycle


26) How many independent properties are required to completely fix the equilibrium state of a gaseous compound state? 

Ans. 2


27) Only those processes are possible in nature which would give an entropy ____ for the system and the surroundings together.

Ans. increase


28) When the potential gradient is ____, the entropy change of the  universe is ____ 

Ans. infinitesimal, zero


29) At equilibrium, the isolated system exists at the peak of the entropy￾hill and

Ans. dS=0


30) When work is dissipated into internal energy, what is the change in the disorderly motion of molecules?

Ans. Increases


31) When heat is imparted to a system,

Ans. the disorderly motion of molecules increases and the entropy of the system increases 


32) Which of the following relation is correct?

Ans. S=K*lnW


33) When does the entropy of a system become zero?

Ans. W=1


34) According to the Boltzmann,

Ans. he introduced the thermodynamic probability with each state, increase 

in entropy implies that the system proceeds by itself towards a state of 

higher thermodynamic probability; an irreversible process goes on 

happening until the most probable is achieved.


35) Phase space is a ________.

Ans. 6 Dimensional Space


36) Maxwell-Boltzmann law is for the ________ 

Ans. Distinguishable particles


37) The Maxwell-Boltzmann law is given by the expression ________

Ans. 1/e (α+EkT)


38) Maxwell-Boltzmann statistics cannot be applied to _____________

 Ans. Photons


39) The ratio of rms velocity to most probable velocity is ________ 

Ans. √3: √2


40) The average kinetic energy associated with each degree of freedom is 

________

Ans. kT/2


41) The density of molecules is maximum at which speed? 

Ans.Vp


42) What would be the most probable velocity for one Oxygen molecule at 

300 K? 

Ans. 714 m/s


43) Mass of A is 4 times that of B. What is the ratio of their mean velocities?

Ans. 1: 2


44) What is the Kinetic Energy of 2 g of oxygen at -23℃? 

Ans. 194.86 J


45) What is the rms speed of methane at 27℃? 

Ans. 678 m/s


46) The study of the flow of heat or any other form of energy in to or out of a system undergoing physical or chemical change is called ------

Ans. Thermodynamics


47) The third law of thermodynamics states that in the limit T→0

Ans. S=0


48) Planck proposed the relationship between the entropy of a system and  the thermodynamic probability is given by the equation _______

 Ans. S=klnw


49) The vibrational partition function equation is given by ___________

Ans. qvib =1/1-e-hυ/kT 


50) The phosphorescence is otherwise known as -------------

Ans. delayed fluorescence





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