Using the equations N2 (g) + 3 H2 (g) → 2 NH3 (g) AH° = -91.8 kJ/mol C(s) + 2 H2 (g) CH4 (g) AH° = -74.9 kJ/mol H2 (g) + 2 C(s) + N2 (g) → 2 HCN (g) AH° = 270.3 kJ/mol Determine the enthalpy (in kJ/mol) for the reaction CH4 (g) + NH3 (g) → HCN (g) + 3 H2 (g). w

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here

Which substance can be broken down by chemical means

Why must humans find substitutes for many minerals found on earth? (a) form at an extremely slow rate (b) controlled by other countries (c) too deep in the earth to collect