1.

Define and explain the term, enthalpy or heat of reaction.

Answer»

<P>

Solution :Enthalpy or HEAT of reaction : The enthalpy of a chemicalreaction is the difference between the sum of the enthalpies of products and that of the reactants with every substance in a definite physicalstate and in the amounts (moles) represented by the coefficients in the BALANCED equation.
Explanation : Consider the following GENERAL reaction,
`aA + bB to cC +dD`
The heat of the reaction `DeltaH` is the difference in sum of enthalpies ofproducts and sum of enthalpies of reactants.
`therefore DeltaH = sum H_("products") - sum H_("reactants")`
` =[CH_(c) +dH_(D)] - [aH_(A)+bH_(B)]`
` =sum""_(p)H - sum""_(R)H`
where H represents enthalpy of the substance.
For endothermic reaction, `DeltaH` is positive,`(DeltaH gt 0)`
For exothermic reaction, `DeltaH` is negative `(DeltaHlt 0)`.


Discussion

No Comment Found

Related InterviewSolutions