19.32
Predict the sign of ΔSsys for each of the following processes:
(a) molten Fe solidifies;
(b) LiCl(s) is formed from Li(s) and Cl2(g);
(c) sinc metal dissolves in hydrochloric acid, forming ZnCl2(aq) and H2(g);
(d) silver bromide precipitates upon mixing AgNO3(aq) and KBr(aq).
19.34
Using Appendix C to compare the standard enthalpies at 25ºC for the following pairs of substances. For each pair, explain the difference in entropy values.
19.34
Using Appendix C to compare the standard enthalpies at 25ºC for the following pairs of substances. For each pair, explain the difference in entropy values.
(a) CuO(s) and Cu2O(s);
(b) 1 mol N2O4(g) and 2 mol NO2(g);
(c) CH3OH(g) and CH3OH(l);
(d) 1 mol PbO(s) plus 1 mol CO2 and 1 mol PbCO3(s).
19.38
Calculate ΔSo values for the following reactions by using tabulated So values from Appendix C. In each case, explain the sign of So.
(a)N2H4(g) + H2(g) → 2NH3(g)
(b) Al(s) + 3Cl2 → 2AlCl3
(c) Mg(OH)2 + 2HCl (g) → MgCl2(s) +2H2O(l)
(d) 2CH4 → C2H6(g) + H2(g)
19.38
Calculate ΔSo values for the following reactions by using tabulated So values from Appendix C. In each case, explain the sign of So.
(a)N2H4(g) + H2(g) → 2NH3(g)
(b) Al(s) + 3Cl2 → 2AlCl3
(c) Mg(OH)2 + 2HCl (g) → MgCl2(s) +2H2O(l)
(d) 2CH4 → C2H6(g) + H2(g)