Find out the temperature of ellingham diagrams, Chemistry

Assignment Help:

Q. Find out the temperature of Ellingham diagrams?

Ellingham diagrams are very useful for finding out the temperature at which appreciable reaction occurs. The lower the ΔG0 /r graph of an element is on the diagram, the more tables

Its oxide is relative to dissociation into element and oxygen. Such elements will reduce the oxides of other elements that are ΔG0 /r graph appears above them on the diagram at a given temperature. As we have seen above, carbon-reduces ZnO above 1173 K, but below 1173 K zinc will reduce CO. Since the ΔG0 / T graph of C/CO system slopes downwards, it will eventually be below all other graphs at sufficiently high temperatures. Therefore, theoretically carbon will reduce all oxides. But difficulties in obtaining very high temperatures cheaply and the formation of carbides prevent the preparation of the more electropositive metals by this method: It is also clear from the Ellingham diagrams that hydrogen can be used as a reducing agent for the oxides of those elements whose ΔG0 /r graphs are above that of hydrogen in the diagram. Thus hydrogen can reduce the oxides of tungsten, lead, antimony, copper, nickel, zinc and cadmium.

Figure shows the Ellingham diagram for sulphides of various elements. You can see from the diagram that carbon and hydrogen are not effective reducing agents for metal sulphides. Therefore, sulphides are first roasted in air to convert them to oxides, which are then reduced.

451_Find out the temperature of Ellingham diagrams.png

The Ellingham diagram for chlorides is shown In Fig.  1t can be concluded from the diagram that carbon is useless as a reductant for chlorides, but hydrogen can be used for his

purpose, specially at higher temperatures.

2271_Find out the temperature of Ellingham diagrams1.png


Related Discussions:- Find out the temperature of ellingham diagrams

Moles, How many moles of O2 are produced when 0.400 mol of KO2 reacts in th...

How many moles of O2 are produced when 0.400 mol of KO2 reacts in this fashion? 4KO2+2CO2 ----> 2K2CO3+3O2

Moles!, a tablet of extra strength tylenol contains 5.00x10^2 mg of acetami...

a tablet of extra strength tylenol contains 5.00x10^2 mg of acetaminophen. Calculate the number of moles of acetaminophen present in one tablet of extra strength tylenol?

The valency of phosphorus, The valency of phosphorus in H3 PO 4   is: (...

The valency of phosphorus in H3 PO 4   is: (1) 2   (2) 5        (3) 4                           (4) 1 Ans: 5

P block, why ionisation energy of aluminium is greater then Ga?

why ionisation energy of aluminium is greater then Ga?

Explain the compound decarboxylates, Explain The compound decarboxylates ...

Explain The compound decarboxylates The compound decarboxylates; it is a disubstituted malonic acid in which the two a substituents are connected within a ring. The net effect

Conformation, Which one is most stable form of 1,3 Di tertiary butyl cycloh...

Which one is most stable form of 1,3 Di tertiary butyl cyclohexane?

The present atomic weight scale is based on, The present atomic weight scal...

The present atomic weight scale is based on: (1) C 12                   (2) O 16        (3) H 1                      (4)C 13 Ans:  C 12

Atomic structure-electrons and nuclei, Electrons and nuclei   The fami...

Electrons and nuclei   The familiar planetary model of the atom was proposed by Rutherford in 1912 following experiments by Geiger and Marsden showing that all the mass of an

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