The graph shows how shows how
-
a. Why can Mg be used to reduce ZnO to Zn at all temperatures, but Zn cannot be used to reduce MgO to Mg at any temperature?
b. Why can C be used to reduce ZnO to Zn at some temperatures but not at others? At what temperatures can carbon be used to reduce zine oxide?
c. Is it possible to produce Zn from ZnO by its direct decomposition without requiring a coupled reaction? If so, at what approximate temperatures might this occur?
d. Is it possible to decompose CO to C end
e. To the set of graphs, add straight lines representing the reactions
given that the three lines representing the formation of oxides of carbon intersect at about 800 eC. [Hint: At what other temperature can you relate and temperature?] The slopes of the three lines described above differ sharply Explain why this is so—that is, explain the slope of each line in terms of principles governing Gibbs energy change.
f. The graphs for the formation of oxides of other metals are similar to the ones shown for Zn and Mg: that is. they all have positive slopes Explain why carbon is such a good reducing agent for the reduction of metal oxides.
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