Formation Equations Video Lessons

Concept:

# Problem: Standard Enthalpies (or Heats) of Formation, ΔH°f , at 298 KSubstanceΔH°f (kJ/mol)Na(s)0.0Na(g)107.5Cl(g)121.3Cl2(g)0.0NaCl(s)-411.2Pb(s)0.0Pb(g)195.2Pb(NO3)2(s)-451.9N(g)472.7N2(g)0.0O(g)249.2O2(g)0.0O3(g)142.7Write equations for the formation of (a) NaCl(s) and (b)Pb(NO3)2(s) from their respective elements in their standard states. Include the value of ΔH°f for each equation.

###### FREE Expert Solution

Standard enthalpy of formation (ΔH˚f) refers to the enthalpy change for the formation of 1 mole of a compound from its elements in their standard states.

(a) NaCl(s)

90% (441 ratings)
###### Problem Details

Standard Enthalpies (or Heats) of Formation, ΔH°f , at 298 K

 Substance ΔH°f (kJ/mol) Na(s) 0.0 Na(g) 107.5 Cl(g) 121.3 Cl2(g) 0.0 NaCl(s) -411.2 Pb(s) 0.0 Pb(g) 195.2 Pb(NO3)2(s) -451.9 N(g) 472.7 N2(g) 0.0 O(g) 249.2 O2(g) 0.0 O3(g) 142.7

Write equations for the formation of (a) NaCl(s) and (b)Pb(NO3)2(s) from their respective elements in their standard states. Include the value of ΔH°f for each equation.