A) the standard enthalpy of an overall reaction is the sum of the enthalpy changes in individual reactions
B) enthalpy of formation of a compound is same as the enthalpy of decomposition of the compound into constituent elements, but with opposite sign
C) at constant temperature the pressure of a gas is inversely proportional to its volume
D) the mass of a gas dissolved per litre of a solvent is proportional to the pressure of the gas in equilibrium with the solution
Correct Answer: A
Solution :
According to second law of thermochemistry the law states that the total heat change \[(\Delta H)\]accompanying a chemical reaction is the same whether the reaction takes place in one or more steps. It means that heat of a reaction depends only on the initial reactants and final products and not on intermediate products that may be formed. Now \[\Delta H=\Delta {{H}_{1}}+\Delta {{H}_{2}}+\Delta {{H}_{3}}\] Enthalpy change in a reaction is always constant and independent of the path followed.You need to login to perform this action.
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