Use Hess's law and the following equations to calculate ΔH for the reaction N2(g) + 2O2(g) N2O4(g). (Show your work.) 2NO2(g) N2O4(g) ΔH = –57.0 kJ/mol
N2(g) + O2(g) 2NO(g) ΔH = 180.6 kJ/mol
2NO2(g) 2NO(g) + O2(g) ΔH = 114.4 kJ/mol

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?

Which of these is an example of pseudoscience? a) predicting the time of sunrise based on data on position of earth b) predicting the date of the moon phases based on data on position of earth c) predicting eclipses based on the position of the sun and the moon d) predicting future events in a person's life based on the position of the moon