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The enthalpy change for a reaction does not depend upon the

  • Option 1)

    physical states of reactants and products

  • Option 2)

    use of different reactants for the same product

  • Option 3)

    nature of intermediate reaction steps

  • Option 4)

    difference in initial or final temperatures of involved substances.

 

Answers (1)

As we learnt in 

Hess's Law -

The total amount of heat change in a chemical reaction is the same whether the reaction is carried  out in one or several steps by one or more methods.

- wherein

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

\Delta H= 393.5\, kj

C_{(s)}+\frac{1}{2}O_{2(g)}\rightarrow CO_{(g)}

\Delta H_{1}= 110.5\, kj

CO_{(g)}+\frac{1}{2}O_{2(g)}\rightarrow CO_{2(g)}

\Delta H_{2}= 283.0\, kj

\Delta H= \Delta H_{1}+\Delta H_{2}

 

 Hess's law of constant heat summation states that regardless of the multiple stages or intermediate steps of reaction that total enthalpy change for the reaction is the sum of all changes.

The enthalpy of a chemical process is independent of the path taken from the initial and the final state.


Option 1)

physical states of reactants and products

this is the incorrect option    

Option 2)

use of different reactants for the same product

this is the incorrect option    

Option 3)

nature of intermediate reaction steps

this is the correct option    

Option 4)

difference in initial or final temperatures of involved substances.

this is the incorrect option    

Posted by

Sabhrant Ambastha

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