The reaction of cyanamide, NH2CN(s), with oxygen was run in a bomb calorimeter, and E was found to be -742.7 kJ/mol of NH2CN(s) at 298 K. Calculate...

The reaction of cyanamide, NH2CN(s), with oxygen was run in a bomb calorimeter, and E was found to be -742.7 kJ/mol of NH2CN(s) at 298 K. Calculate H298 for the reaction. NH2CN(s) + 3/2; O2 --->N2 + CO2 + H2O(l) A. -727.8 kJ B. -737.7 kJ C. -741.5 kJ D. -742.7 kJ E. none of the aboveGiven: SO2 + 1/2 O2 ---> SO3 H°rxn = -99kJ ---- What is the enthalpy change for the following reaction? 2 SO3 ---> O2 + 2 SO2 H°rxn = ? A. 99 kJ B. -198 kJ C. 49.5 kJ D. -99 kJ E. 198 kJFind the standard enthalpy of formation of ethylene, C2H4(g), given the following data: C2H4(g) + 3 O2(g) ---> 2CO2(g) + 2 H2O(l) H°f = -1411 kJ ; C(s) + O2(g) ---> CO2(g) H°f = -393.5 kJ ; H2(g) + 1/2 O2(g) ---> H2O(l) H°f = -285.8 kJ A. 731 kJ B. 87 kJ C. 1.41 x 103 kJ D. 52 kJ E. 2.77 x 103 kJI have worked these three questions out but I am not sure that the answer that I have is correct. Can you work them and explain step by step how you did them