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The internal energy change when a system goes from state A to B is 40 kJ/mole. If the system goes from A to B by  a reversible path and returns to state A by  an irreversible path what would be the net change in internal energy?

  • Option 1)

    40 kJ

  • Option 2)

    > 40 kJ

  • Option 3)

    < 40 kJ

  • Option 4)



Answers (1)

As we learnt in 

Lavasier and Laplce's Law -

Enthalpy of decomposition of a compound is numerically equal to the formation of that compound and only sign changes.

- wherein

C_{(s)}+O_{2(g)}\rightarrow CO_{2}

\Delta H= 393.5 \, KJ

CO_{2(g)}\rightarrow C_{(s)}+O_{2(g)}

\Delta H= -393.5 \, KJ


 For a cyclic process the net change in the internal energy is zero because the change in internal energy does not depend on path.

Option 1)

40 kJ

this is incorrect option

Option 2)

> 40 kJ

this is incorrect option

Option 3)

< 40 kJ

this is incorrect option

Option 4)


this is correct option

Posted by

Sabhrant Ambastha

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