3. Calculate the standard enthalpy of reaction for the following reactions: A) 2 NH3(g) + 7/2 O2(g) → 2 NO2(g) + 3 H2O(g)

B) Fe2O3(s) + 3CO(g) → 2 Fe(s) + 3 CO2(g)

C) 2BaSO4(s) → 2BaO(s) + 2SO2(g) + O2 (g)

BASED ON THE ABOVE EQUATIONS - CALCULATE THE FOLLOWING:

(A)Calculate the heat required to combust 25.0 g of ammonia.

(B) Calculate the heat required to produce 25.0 g of iron from iron(III) oxide.

(C) Calculate the heat required to decompose 10.0 g of barium sulfate. Δ Hfo (BaO) = -553.5 kJ/mol

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

When the water vapor cools it condenses select a number that represents his process on the

Based on its chemical properties, identify the position of each chemical family on the periodic table.