The entropy of a perfectly crystalline material is zero at 0°

Subject

Chemistry

Class

JEE Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

1.

Which of the following sets of qunatum numbers correct?

  • n =5, l=4, m=0, s=+1/2

  • n= 3, l=3, m=+3, s= +1/2

  • n=6, l=0, m=+1, s= =1/2

  • n=4, l= 2, m=+2, s=0


2.

Which of the following behaves as Lewis acid and not as Bronsted acid ?

  • HCl

  • H2SO4

  • HSO3-

  • SO3


3.

The pair of elements having approximately equal ionisation potential is

  • Al, Ga

  • Al, Si

  • Al, Mg

  • Al, B


4.

Water is well known amphoprotic solvent. In which chemical reaction water is behaving as a base?

  • H2SO4 + H2O → H3O+ HSO4-

  • H2O + H2O → H3O+ + OH-

  • H2O + NH2- → NH+ OH-

  • H2O + NH3 → NH4+ + OH-


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5.

Which of the following is not a equilibrium ?

  • Ice  Water

  • I2(s)  I2(g)

  • S (l)  S (g)

  • 3O2 2O3


6.

2.5 L of NaCl solution contain 5 moles of the solute. What is the molarity ?

  • 5 M

  • 2 M

  • 2.5 M

  • 12.5 M


7.

The calculated bond order in O2- ions is

  • 1

  • 1.5

  • 2

  • 2.5


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8.

The entropy of a perfectly crystalline material is zero at 0°C. This is statement of

  • first law of thermodynamics

  • second law of thermodynamics

  • third law of thermodynamics

  • law of conservation of energy


C.

third law of thermodynamics

(a) First law of thermodynamics states that energy can neither be created nor be destroyed but one form of energy can be converted into another.

(b) Second law of thermodynamics states that for a spontaneous process in an isolated
system, the change in entropy is positive.

(c) Third law ofthermodynamics states that the entropy of a perfectly crystalline substance is  zero at 0°C.

(d) Law of conservation of energy states that energy can neither be created nor be destroyed.

Hence, the given statement is third law of thermodynamics.


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9.

In acidic medium, the equivalent weight of  K2Cr2O7 ( Mol. wt. = M) is

  • M

  • M/2

  • M/3

  • M/6


10.

When a metal atom combines with a non-metal atom, the non-metal atom will

  • lose electrons and decrease in size

  • lose electrons and increase in size

  • gain electrons and decrease in size

  • gain electrons and increase in size 


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