Problem: Standard thermodynamic quantities for selected substances at 25 °C SubstanceΔHf ( 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)142.7What is the value of ΔH for this reaction? (Formation of Pb(NO3)2(s))
FREE Expert Solution
We are asked what is the value of ΔH for this reaction? (Formation of Pb(NO3)2(s))
Balanced reaction:
Pb(s) + N2(g) + 3 O2(g) → Pb(NO3)2(s)
Since this is a formation equation, the ΔH°f of the product is already the ΔH°rxn.
This is because the ΔH°f of reactants are all zero.
Problem Details
Standard thermodynamic quantities for selected substances at 25 °C
| Substance | ΔHf ( 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 |
What is the value of ΔH for this reaction? (Formation of Pb(NO3)2(s))
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Enthalpy of Formation concept. You can view video lessons to learn Enthalpy of Formation. Or if you need more Enthalpy of Formation practice, you can also practice Enthalpy of Formation practice problems.