Answer to Question #312782 in General Chemistry for Krix

Question

B. Hess’s Law

1. Using Hess’ Law and the following information calculate the heat of formation of the plant hormone ethylene, C2H4 in the equation: 2 C(s) + 2 H2(g) → C2H4(g)

chem 13A.png

2. Calculate the value of Ho/kJ for the following reaction using the listed thermochemical equations:

P4O10(g) + 6 PCl5(g) 10 Cl3PO(g)

1/4 P4(s) + 3/2 Cl2(g) --> PCl3(g) ∆Ho = -306.4

P4(s) + 5 O2(g) --> P4O10(g) ∆Ho= -2967.3

PCl3(g) + Cl2(g) --> PCl5(g) ∆Ho= -84.2

PCl3(g) + 1/2 O2(g) --> Cl3PO(g) ∆Ho = -285.7

Answer 1

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