Enthalpy and hess’ law, Chemistry

Assignment Help:

 

The enthalpy change (ΔH) in a reaction is equal to the heat input under conditions of constant pressure and temperature. It is not equal to the total energy change, as work may be done by expansion against the external pressure. The corrections are usually small, and enthalpy is used as a measure of the energies involved in chemical reactions. Endothermic reactions (positive ΔH) are ones need a heat input, and exothermic reactions (negative ΔH) give a heat output.

Hess' Law states that ΔH does not rely on the pathway taken between initial and final states, and is a consequence of the First Law of Thermodynamics, which asserts the conservation of total energy. It describes a schematic thermodynamic cycle where the ΔH can be expressed as the sum of the values for individual steps:

 

2056_Untitled.png


Related Discussions:- Enthalpy and hess’ law

Explain the heat of formation of the gases, Take these values into account ...

Take these values into account and comment on the relation between the heat of formation of the gases and the vibrational frequencies again.

Catalysis, #question:- What are the theories of catalysis?

#question:- What are the theories of catalysis?

What is standard electrode potentials of lanthanides, Q. What is standard e...

Q. What is standard electrode potentials of lanthanides? The standard electrode potentials of lanthanides for the half reaction Ln 3+ (aq) + 3e ----------------> Ln (s)

Physical properties of benzoic acid, Physical Properties of Benzoic Acid ...

Physical Properties of Benzoic Acid (a) Benzoic Acid is a white crystalline solid. (b) Benzoic Acid has m.p. 394 K. (c) Benzoic Acid is sparingly soluble in cold water bu

Actinium and the actinides, ACTINIUM AND THE ACTINIDES Following actini...

ACTINIUM AND THE ACTINIDES Following actinium (group 3) are the 14 components of the actinide series (represented by the symbol An) combined with progressive filling of the 5

Project, Preparation of saturated calomel electrode and determination of st...

Preparation of saturated calomel electrode and determination of standard potentials of electrodes such as Cu 1 Cu, Zn 1 Zn, etc. Comparison of the potential values with values from

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd