Final answer:
The standard enthalpy of formation for NO₂(g) is depicted by the reaction: N₂(g) + O₂(g) → NO₂(g), ΔH°f = +33.2 kJ/mol, which represents the formation of one mole of NO₂(g) from its elements in their standard states.
Step-by-step explanation:
The standard enthalpy of formation for nitrogen dioxide gas, NO₂(g), at 25°C is represented by the reaction equation where one mole of nitrogen gas (N₂) reacts with one mole of oxygen gas (O₂) to form one mole of NO₂(g). This reaction can be expressed as:
N₂(g) + O₂(g) → NO₂(g), ΔH°f = +33.2 kJ/mol
It is important to note that the standard enthalpy of formation (ΔH°f) is defined for the formation of one mole of a compound from its elements in their standard states at a pressure of 1 atm and a temperature of 25 °C. Therefore, the reaction given is the correct depiction for calculating the standard enthalpy of formation of NO₂(g).