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

Describe linkage isomerism, Q. Describe Linkage Isomerism? Some ligands...

Q. Describe Linkage Isomerism? Some ligands can coordinate to the metal through different donor ato...s present in the ligand. They are called ambidentate ligands and they can

For p-orbital, For p-orbital, the magnetic quantum number has value: (1...

For p-orbital, the magnetic quantum number has value: (1) 2        (2) 4, - 4          (3) - 1, 0, +1              (4) 0 Ans: - 1, 0, +1

Can you explain texture, Q. Can you explain Texture? Texture indicates ...

Q. Can you explain Texture? Texture indicates the characteristic of a food and would include descriptive parameters like graininess, softness, chewiness, brittleness etc. The t

Explain the purity tests of sesame oil, Q. Explain the Purity Tests of sesa...

Q. Explain the Purity Tests of sesame oil? Purity tests for oils/fats would include analyzing the samples for the presence of sesame oil, cottonseed oil, linseed oil, argemone

Two similar non-metallic atoms, The electron pair which forms a bond betwee...

The electron pair which forms a bond between two similar non-metallic atoms will be: (1) Dissimilar shared between the two (2) By complete transfer from one atom to other

Draw the structural formulas of both isomeric free acids, In solid state ch...

In solid state chemistry the CN 2 2- ion shows constitutional isomerism. The free acids of both anions (at least in the gas phase) are known. Illustrate the structural formul

Extraction of aluminium, Q. Extraction of Aluminium? Aluminium cannot b...

Q. Extraction of Aluminium? Aluminium cannot be extirpated economically from the silicate minerals. Therefore bauxite is the most important ore for the extraction of alumimum,

Write electron configuration for a neutral atom of silicon, Q. Write electr...

Q. Write electron configuration for a neutral atom of silicon? Writing Electron Configurations by means of Noble-Gas Notation Use noble-gas notation to write the electron confi

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