Consider each of the following reactions and decide whether thestandard entropy change for the reaction will be large &positive; or small; or large & negative. 1. large&negative2. large&positive 3.small
a) H2(g) + Cl2(g) = 2 HCl(g) |
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b) 2 Na(l) + H2(g) = 2 NaH(s) |
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c) 2 H2O(l) = 2 H2(g) +O2(g) |
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d) C(s) + H2O(g) = CO(g) + H2(g) |
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e) Cu(s) + 2 H2SO4(aq) =CuSO4(aq) + 2 H2O(l) + SO2(g) |
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f) BaSO4(s) + 2 H2O(g) =BaSO4.2H2O(s)
2. Identify the true statement(s) regarding the entropy ofchemical substances.
| All pure substances have a positive entropy at roomtemperature. |
| The dissolution of an ionic salt in water usually leads to anincrease in entropy of the system (salt + water). |
| So(one mole O3(g)) > So(onemole O2(g)) at 25oC. |
| The entropy of ice at 0oC is lower than that of waterat 0oC. |
| When a metallic crystal is heated, its entropy increases due toincreasing atomic vibrations. |
