Chapter 9, Problem 9.154MP

Hydrazine, a component of rocket fuel, undergoes combustion to yield N₂ and H₂O:
$N_2{H}_4\left(l\right)+O_2\left(g\right)\to N_2\left(g\right)+H_{2}O\left(l\right)$
(a) Draw an electron-dot structure for hydrazine, predict the geometry about each nitrogen atom, and tell the hybridization of each nitrogen.
(b) Use the following information to set up a Hess's law cycle, and then calculate $\Delta H°$ for the combustion reaction. You will need to use fractional coefficients for some equations. $2N{H}_3\left(g\right)+3N_2\left(g\right)\to 4N_2\left(g\right)+3H_{2}O\left(l\right)$ $\Delta H°=-1011.\text{2 kJ}$
$N_{2}O\left(g\right)+3H_2\left(g\right)\to N_2{H}_4\left(l\right)+H_{2}O\left(l\right)$ $\Delta H°=-317.\text{2 kJ}$
$4N{H}_3\left(g\right)+O_2\left(g\right)\to 2N_2{H}_4\left(l\right)+2H_{2}O\left(l\right)$ $\Delta H°=-286.0\text{ kJ}$
$H_{2}O\left(l\right)$
$\Delta H{°}_{\text{f}}=-285.8\text{ kJ/mol}$
(c) How much heat is released on combustion of 100.0 g ofhydrazine?