Question

Hess’s law of constant heat summation is an application of : a) Kirchhoff’s law b) First law of thermodynamics c) Second law of thermodynamics d) Entropy 47. ​

Answer 1

Explanation:

second law of thermodynamics

Answer 2

Answer:

Hess’s law of constant heat summation is the application of first law of thermodynamics.

Therefore, the option (b) is correct.

Explanation:

• The energy change accompanying chemical reactions are governed by general principle of known as Hess's law.
• It states that the total amount of heat absorbed or evolved for a chemical reaction is same whether the reaction takes place in single step or number of steps.
• The amount of enthalpy change depends upon the enthalpy of reactants or enthalpy of products, irrespective of their path.
• The thermodynamics of Hess's law is enthalpy is a state function. therefore, the enthalpy change depends upon initial and final state.
• Hess's law is in accordance with the law of conservation.
• Mathematically representation of Hess's law:-

                $\triangle H_{net}=\sum H_{r}$

           where, $\sum H_{r}$ is sum of enthalpy change of reactions.

First law of thermodynamics also suggests the conservation of energy.

Therefore, Hess's law based on the first law of thermodynamics because both represents the conversation of energy.