Ammonia reacts with oxygen according to the equation 4nh3(g)+5o2(g)→4no(g)+6h2o(g),δhrxn =−906 kj calculate the heat (in kj) associated with the complete reaction of 155 g of nh3.

Answer is: 2065.15 kJ.
Balanced chemical reaction: 4NH₃ + 5O₂ → 4NO + 6H₂O, ΔHrxn=−906 kJ.
m(NH₃) = 155 g.
n(NH₃) = m(NH₃) ÷ M(NH₃).
n(NH₃) = 155 g ÷ 17 g/mol.
n(NH₃) = 9.118 mol.
Make proportion: 4 mol(NH₃) : 906 kJ = 9.118 mol : Q.
Q = 906 kJ · 9.118 mol / 4 mol.
Q = 2065.15 kJ.