Question

Define stancard enthalpy of formation .Write the chemical equation for the formation of N2O5

Answer 1

The standard enthalpy of formation is defined as the change in enthalpy when one mole of a substance in the standard state (1 atom of pressure and 298.15 K) is formed from its pure elements under the same conditions.

The standard enthalpy of formation is a measure of the energy released or consumed when one mole of a substance is created under standard conditions from its pure elements. The symbol of the standard enthalpy of formation is ΔHf.

Δ = A change in enthalpyo = A degree signifies that it's a standard enthalpy change.f = The f indicates that the substance is formed from its elements

N2O3+O2--->N2O5