69. Using the data in Appendix G, calculate the standard enthalpy change for each of the
following reactions:
(a) Si(s) + 2F₂ (g)
SiF₂ (g)
(b) 2C(s) + 2H₂(g) + O₂(g) →→→ CH,CO₂H(1)
(c) CH₂(g) + N₂(g)
HCN(g) + NH, (g)
(d) CS₂(g) + 3Cl₂(g) → CC1, (g) + S₂Cl₂(g)