Question

Use the standard reaction enthalpies given below to determine δHrxn for the reaction 2NO(g)+O2 (g)→2NO2(g):

a) δHrxn =114kJ
b) δHrxn=216kJ
c) δHrxn =−114kJ
d) δHrxn =−216kJ

Answer 1

The standard reaction enthalpy (ΔHrxn) for the reaction 2NO(g) + O2 (g) → 2NO2(g) is -114.1 kJ, indicating an exothermic reaction where heat is released.

Step-by-step explanation:

To determine the standard reaction enthalpy (ΔHrxn) for the reaction 2NO(g) + O2 (g) → 2NO2(g), we can use the given standard reaction enthalpy. The provided ΔH° for the reaction is -114.1 kJ. This means that when two moles of nitric oxide (NO) gas react with one mole of oxygen gas (O2) to form two moles of nitrogen dioxide (NO2) gas, 114.1 kJ of heat is released. Therefore, the ΔHrxn for this reaction is -114.1 kJ, which corresponds to option (c).ΔHrxn is a thermodynamic quantity that represents the heat change during a reaction, and in this case, the negative sign indicates that the reaction is exothermic.