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Entropy Change for Reactions

Using the data sheet (see attachment) calculate delta S values for the following reactions. In each case explain the sign of delta S.

N2H4(g) + H2(g) --> 2NH3(g)
2Al(s) + 3Cl2(g) --> 2AlCl3(g)
Mg[OH]2(s) + 2Hcl(g) --> MgCl2(s) + 2H20(l)
2CH4(g) --> C2H6 + H2(g)


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1. dH = entropy of products - entropy of reactants

dH = [2x 192.5] - [238.5 + 130.58] = 15.92 J/molK

There is a small increase in entropy as the gases become somewhat smaller and hence more ...

Solution Summary

The entropy change dS is calculated for some reactions. The sign of the entropy change is also explained in each case.