Use the values of Hf° in Appendix 4 to calculate H° for the following reactions.

(a) C2H5OH(l) + 3 O2(g) 2 CO2(g) + 3 H2O(g)
(b) SiCl4(l) + 2 H2O(l) SiO2(s) + 4 HCl(aq)
(c) MgO(s) + H2O(l) Mg(OH)2(s)

Values:
C2H5OH = -278
O2 = 0
CO2 = -393.5
H2O(l) = -286
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SiCl4 = -687
H2O(g) = -242
SiO2 = - 911
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MgO = -602
H2O(l) = -286
Mg(OH)2 = -925