The standard enthalpy of formation of CF2ClCF2Cl(g) (ΔfH∘300) at 1 bar and 300 K from its constituent elements in their standard states is −900 kJ mol−1. (Given, R=8.3 J K−1 mol−1)The standard internal energy of formation (Δ∘fU300) at the same pressure and temperature is:

The standard enthalpy of formation of CF2ClCF2Cl(g) (ΔfH∘300) at 1

1.	The standard enthalpy of formation of CF2ClCF2Cl(g) (ΔfH∘300) at 1 bar and 300 K from its constituent elements in their standard states is −900 kJ mol−1. (Given, R=8.3 J K−1 mol−1)The standard internal energy of formation (Δ∘fU300) at the same pressure and temperature is:
Answer» The standard enthalpy of formation of $C F_{2} C l C F_{2} C l (g)$ $(Δ_{f} H_{300}^{\circ})$ at $1 bar$ and $300 K$ from its constituent elements in their standard states is $- 900 {kJ mol}^{- 1}$ . (Given, $R = 8.3 {J K}^{- 1} {mol}^{- 1}$ ) The standard internal energy of formation $(Δ_{f}^{\circ} U_{300})$ at the same pressure and temperature is: