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

Atoms, What did thomson''s model of an atom look like, when did he discover...

What did thomson''s model of an atom look like, when did he discover the atom, where did he discover it, how did he, who helped him, when did he die, how did he die??????

Organic reactions and their mechanism, what are the types of Organic reacti...

what are the types of Organic reactions and their mechanism

Vespr, Give the name of the molecular shape of each of the following. (1 m...

Give the name of the molecular shape of each of the following. (1 mark each) 1) silicon tetraiodide

Stucture of atom, penetration power of proton is more/less than?

penetration power of proton is more/less than?

Uses of formic acid - carboxylic acids, Uses of Formic acid - Carboxylic ac...

Uses of Formic acid - Carboxylic acids (a) Formic acid is used in the laboratory for preparation of carbon monoxide. (b) Formic acid is used in the preservation of fruits.

Concentration, What does concentration exactly mean?

What does concentration exactly mean?

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